Longest pondering in a standard-time control game

Question

Inspired by the LiChess "French leave" question:

In a standard time-control you can think almost two hours about your move, and even two-and-a half or three if you blitzed beyond the 40 move control. Personally, I recall the one or other opponent of mine thinking a whopping hour about a tempting sacrifice I allowed them to make - bad idea, they regularly lost when I produced even more chaos on the board and they wished they had more time to analyze :P

Thus, my question: What is the longest reported time for a single move under 2h+X/40? (Including Fischer bonus, what argueably makes this even easier. Non-OTB is allowed too, which has the advantage of the data being explicitely recorded.) Tal's "Hippo incident" comes to mind, and Sämisch was an expert for this in almost every game. Still, I lack concrete values.

Answer 1

Tal wrote* about this game:

it was here that Uhlmann established his record, thinking over the move 12...exf5 for 1 hour 50 minutes

Judging from other comments by Tal about this game, I think the time control must have been 2 hours and 30 minutes for the first 40 moves.

[Title "Mihail Tal-Uhlmann, Wolfgang, Alekhine Memorial, Moscow Russia, 11/30/1971"]
[FEN ""]
[startply "23"]

1. e4 e6 2. d4 d5 3. Nd2 c5 4. Ngf3 Nc6 5. Bb5 dxe4 6. Nxe4 Bd7 7. Bg5 Qa5+ 8. Nc3 cxd4 9. Nxd4 Bb4 10. O-O Bxc3 11. bxc3 Qxc3 12. Nf5 exf5 13. Re1+ Be6 14. Qd6 a6 15. Bd2 Qxc2 16. Bb4 axb5 17. Qf8+ Kd7 18. Red1+ Kc7 19. Qxa8 1-0

(*) The Life and Games of Mikhail Tal, Everyman Chess (2003), p. 401.