At least a dozen would be my guess. Larry was also a big fan of the Advanced Tobruk System and pre-ordered most games from Critical Hits.
Both Mike B. and Ray T. are aware of his passing (and I would count them among his friends) so I would expect them to send the money back to Larry's widow in due time.
Larry and I exchanged a dozen emails these past few years and I was always surprised how optimistic he was about his pre-orderrs. He will be missed.