I know SCD notes that Bush may have gotten 100 of the cards. While regular print sheets may involve 132 cards maybe not all Topps sheets were of that size. The Topps 1984 Encased "set" is 66 cards...see the Head in the Box thread. I suppose it may have been double printed. And the Topps 1973 Reprints for1953 was 8 cards. I think the 1977 Proof sheet with R Jackson as an Oriole is a smaller sheet too.
Topps did other 1 card issues....the 76 and 91 Joe Garogiola card, the 84 Darryl Palmer card, the Bowie Kuhn tribute card. I have no idea how many of each was produced, or the Bush card. The Palmer card seems to be the scarcest of the bunch. Garogiola used his as business cards, often signed, so they often show up. Surely Bush gave many away and when prices in auctions went up, more seemed to surface. I paid too much for mine
Cool hobby mystery