I wrote it was just a guess.
A year ago I was at AB Linn's place in NC. I had a list of Gasser specific parts I was going down. He finally said something like this. "We used to go to auctions after the multifuel came out and there would be OA331's lined up in rows. Brand new never fired up in the can. Nobody wanted them, they were worth more scrap than parts. I bought some, they sat for years, nobody even asked about them. I scrapped them out 5-10 years ago just to make room." When the military started taking running, driving Gasser trucks and putting the multi fuel engine in, they reduced the supply down to just about the only survivors being ones already auctioned out of the inventory.
My two were bought by an individual some time around 1958 or 1959. I have no idea how many others were sold to individuals or other countries before they all got converted. I was just going by what I have seen regarding other Gasser owners posting up here, MVM and the MVPA magazines.
However, even with the small numbers. Or seemingly small number of trucks. Parts are still readily available. Antelope Valley and a few others that advertise in the mentioned magazines have just about all the Gasser specific parts you could ever want. The OA 331 being made as a civilian engine for years helps too.
Since it uses twice the fuel as my whistler, I usually drive it just once a week at most and for parades. The multifuel gets used just about daily. If I had to only have a single duece, it would be the whistler because I could use it for more things.