Hi Geoff,
Your observation "in your games Grandmaster ideas and tricks of the trade lurk all the time" reminded me of the game David Levin (2131)--Edward Gaillard (1880) from the 1980 Pan-American Intercollegiate Team Chess Championship.
Here's the position after 20...h6:
The game concluded,
21. Rf6 (Intending 21...gxf6 22. exf6, with the decisive pair of threats 23. Qg3+ and 23. Qxh6.)
21...Qd8 22. Qe4 (If now 22...g6, then 23. Rxg6+.)
1-0
After the game, teammate Colin McRae remarked that the finish was similar to Fischer-Benko. Here's the position after 18...exd4 in the game he was referring to (from the 1963-4 US Championship):
The game concluded,
19. Rf6 Kg8 20. e5 h6 21. Ne2 1-0
What's funny is that I didn't immediately realize what Colin was referring to. I had found 21. Rf6 as a result of wanting to clear the way for Qe4... without permitting ...f5.
For me, the main benefit of seeing combinations in books seems to be that it further develops my routine for finding and analyzing tactics. But I don't doubt that I've played games in which I recognized an available tactic as a result of having seen it previously.