Well, after looking around, BriteButtons offers a kit that they say is compatible with CGC games and they show how to wire it in.
http://www.britemods.com/britebuttons-.html
I am guessing that CGC's position is they don't support any non-CGC mods of any kind, and that owners do so entirely at our own risk, including voiding part or all of our warranty.
This is entirely understandable from their perspective.
I'd say anything non-approved we do with our games it at our own risk.
Disappointing to a degree, and the board failure from simply putting otherwise common LED bulbs in the coin door causing such an expensive problem is frustrating.
As previous posters have said, fixing that board is probably fairly trivial for a skilled electronics tech that can do small SMD device replacement (which is not me)
RM