@Guymyer:
Yeah, I’m in agreement I’d rather lose fair than cheat. So this leaves with a hard decision. Not inviting said individual would cut group in half down to 2. His brother also plays so if I say no to one the other wouldn’t come. Gotta figure out a way to ensure no cheating.
The second, third and fourth chapters of the novel Goldfinger, in which James Bond is hired by a rich American businessman to figure out whether or not Auric Goldfinger – who’s been fleecing the businessman for a week at double-handed canasta – is cheating, make the point that in order to devise effective countermeasures against a cheat you first have to determine exactly how he’s cheating in the first place. You’ve mentioned that you’ve caught your opponent a few times, so you must already have some idea of what you need to guard against, but your question “Could there have been some cheating on buys and dice play?” suggests that there’s still some uncertainty about what kind of tricks this fellow might be pulling. Reading “Scarne on Cards” for advice (as Bond does in another novel where he’s trying to catch a card cheat; I think it was Moonraker) isn’t going to be of any help to you in an A&A context, but perhaps some of the folks here can offer a few pointers on what types of deceptions they’ve run into in their own A&A games. If (which you indicate is a possibility) there’s some dice-rolling trickery going on, a dice tower might help to eliminate that part of the problem.