Yes, a hearty welcome, Hans Langrock, to our humble forum! 

The whole thing about the Morra is that it can be offered not only on the third move, but the fourth: e.g. 1.e4 c5 2.Nf3 e6 (which is how I have always played the Sicilian) 3.d4 cxd4 4.c3.  So Black's answer to the Morra depends on what move he makes after 2.Nf3.  I, for example, must opt for a method that situates Black's pawn on e6.

Maybe we can get Lenderman or Esserman to post something on this Gambit here as well.

Looking at the Chessbase Site just moments ago I noticed Lawrence Trent has a new CBFT out on The Smith Morra, so it would seem the resurrection of this thread is timely.

I suppose a Morra player need be also quite expert in the equal lines following 2...Nf6.

Tops

Off-topic:

A big welcome to Hannes Langerock, I'm a big fan of your CBM articles, especially your Petrosian QID articles in CBM 132/133.

The reason I never have looked seriously at this is that White;s results have been disastrous in the past. Langrock's main line actually has been tested:

Poenitz,S - Reiners,C [B21]
BdF corr BdF, 1996

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 e6 7.0–0 Be7 8.Qe2 a6 9.Rd1 Bd7 10.Bf4 e5 11.Be3 Nf6 12.Nd5 Nxd5 13.Bxd5 0–0 14.Rac1 Rc8 15.a3 Kh8 16.b4 Qe8 17.Nd2 f5 18.exf5 Bxf5 19.f3 Nd8 20.Rxc8 Bxc8 21.Ne4 Qa4 22.Qd3 Bf5 23.Rb1 Bg6 24.b5 Bf7 25.Rb4 Qa5 26.Bg5 Qc7 27.Bxe7 Qxe7 28.bxa6 bxa6 29.Ra4 Qa7+ 30.Kf1 Qc7 31.Rxa6 Bg6 32.a4 Qc1+ 33.Kf2 Bxe4 34.Bxe4 Nf7 35.Ra8 Rxa8 36.Bxa8 Qb2+ 37.Kg3 Qb4 38.Qf5 Qe1+ 39.Kh3 g5 40.Qe4 Qd2 41.Qc4 d5 42.Bxd5 Nd6 43.Qb3 g4+ 44.fxg4 Qh6+ 45.Kg3 Qf4+ ½–½

Morra threads shouldn't be dead, so I'm trying to put some life into this one. 

I believe that among the ...Bd7 lines the Eliskases line (4...Nc6 5.Nf3 d6 6.Bc4 e6 7.0-0 a6 8.Qe2 Be7 9.Rd1 Bd7 10.Bf4 e5 11.Be3 Nf6) is the only really critical one.
The most interesting answer seems to be 12.Nd5!?. This exchanges a piece, but after 12...Nxd5 13.Bxd5 White has a dominating bishop on d5. The main line continues 13...0-0 14.Rac1 Rc8 15.a3! (gaining space at the queenside)
Now Black's only active plan seems to be 15...Kh8 16.b4 f5, but then after 17.exf5 Rxf5 18.Nd2! the knight is going to e4 and White has nice compensation for the pawn.
According to my database the whole line with 15.a3 has been played 9 times (7x in corr games) with both sides scoring 4,5 points.
After playing the line in more than a dozen online blitz games and doing some analysis with Rybka, I think it is objectively equal, but easier to play for White (especially OTB).   

Thanks for this very informative reply. I stand guilty of sloppy research, I had simply overlooked the existence of this part 7 in CCN 94! It looks very useful, certainly it is nice to have a source that is more thorough than Palkövi and more White-friendly than Silman.

So it appears that Black can be very confident of his chances after 12.Rd2 0-0 13.Rad1, with both 13...h6 and 13...Rc8 looking promising for him? I have a lot of ideas to chew on now (12 b4!? MNb, 12.h3 Senador, 12.Nd5 Zelic, and 12.a3 Rc8 Equidistance [by transposition]), so I will try to stay away from this thread until I have some serious analysis to contribute!

Just some quick thoughts on Senador-Nanjo (12.h3 0-0 Bg5): I like Black after your suggestion of 17...Na5!, but maybe earlier White could have tried 15.Rxd6!? Qc7 (again those double-attack ideas, with ...Nd4 threatened) 16.Rxf6 (or 16.Qd2!? Rfd8! 17.Rxf6) gxf6 17.Nd5 which at the very least looks scary for Black to face over the board.

As for 13...Ne8 the time-loss involved makes me a bit skeptical, shouldn't White be able to drum up at least enough compensation somehow? In CCN 94 the point is made (if I read it right) that by Bg5xe7 White exhanges off his good bishop for Black's bad one, but Be7 is also a typical case of "a bad bishop protecting a good pawn" (according to rebel strategic thinker Mihai Suba). When I play these positions as Black I think of Be7 as the one defensive piece that single-handedly holds the fort on d6, often allowing Black's other pieces to operate on either side of the board (maybe this is just a matter of taste though).

That's why I would love to avoid having to deal with Bg5 altogether, and I have wondered if Black can simply meet the slow 12.h3 with his own slow 12...h6, but of course White can consider both 13.Nh4 and 13.Nd5 a la Zelic in reply and... I need to analyse some more  

I don't think we are being harsh, pointing out these improvements can be useful to White and Black players alike, certainly it would be harsher to have to deal with them over the board.  Besides, Palkövi writing around the year 2000 could have used a reasonably strong engine to check these things.

I recall some excellent articles on the Morra by a certain Jensen in Correspondence Chess News, but I don't think our current Bd7 move order was discussed. I have sometimes wondered what the author might have had in mind...  

I have recently become aware of some games by the strong Philippinian player Senador where he insists on getting his bishop to g5, and is willing to spend a tempo on h3 to safeguard the d4 square. Right now I am inclined to think this is White's best attempt at real compensation. The first of these games was annotated by Gary Lane on ChessPublishing, by the way:

[Event "Asean Open"]
[Site "Bandar Seri Begawan"]
[Date "2001.??.??"]
[Round "4"]
[White "Senador, Emmanuel"]
[Black "Dang Tat Thang"]
[Result "1/2-1/2"]
[ECO "B21"]
[WhiteElo "2433"]
[BlackElo "2273"]

1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 Nc6 5. Nf3 d6 6. Bc4 e6 7. O-O Be7 8. Qe2 a6 9. Rd1 Bd7 10. Bf4 b5 11. Bb3 e5 12. Be3 Nf6 13. h3 O-O 14. Bg5 Be6 15. Bxf6 Bxf6 16. Nd5 Bxd5 17. Bxd5 Rc8 18. a4 Qb6 19. axb5 axb5 20. Bxc6 Rxc6 21. Rd5 Rc5 22. Rad1 Be7 23. Nh2 Rfc8 24. Nf1 Rxd5 25. Rxd5 Rc5 26. Ne3 Bg5 27. Rxc5 dxc5 28. Qg4 Qd8 29. Nd5 g6 30. Qg3 Bf4 31. Qc3 Qd6 32. b3 Bg5 33. Qd3 Qc6 34. Qg3 Bf6 35. Qxe5 Bxe5 36. Ne7+ Kg7 37. Nxc6 Kf6 38. Kf1 Ke6 39. Ke2 b4 40. Nd8+ Ke7 1/2-1/2

[Event "Dato Arthur Tan Malaysian Op"]
[Site "Kuala Lumpur MAS"]
[Date "2007.08.26"]
[Round "11"]
[White "Senador, E."]
[Black "Nanjo, R."]
[Result "1-0"]
[ECO "B21"]
[WhiteElo "2380"]
[BlackElo "2165"]
[Source "Mark Crowther"]

1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 Nc6 5. Nf3 d6 6. Bc4 e6 7. O-O Be7 8.Qe2 a6 9. Rd1 Bd7 10. Bf4 e5 11. Be3 Nf6 12. h3 O-O 13. Bg5 Rc8 14. Bxf6 Bxf6 15. Nd5 Be6 16. Rac1 Bg5 17. Rc3 Bh6 18. a3 b5 19. Ba2 Ne7 20. Rxc8 Bxc8 21. Nc3 Qb6 22. Qd3 Nc6 23. Nd5 Qb8 24. g4 g6 25. Nf6+ Kh8 26. g5 Bg7 27. Qxd6 Qa8 28. Bd5 Bb7 29. Nd7 Rd8 30. Bxc6 Bxc6 31. Nfxe5 Bxd7 32. Nxf7+ Kg8 33. Nxd8 Qxd8 34. Qxd7 Qxg5+ 35. Kh1 Bxb2 36. Qe8+ Kg7 37. Rd7+ Kh6 38. Qf8+ 1-0