Thanks Keith. I think the pinwheel menkos are really attractive cards. Some of them are really common, but I've never seen that particular one before. Perhaps the rarity varies within the set. I just bought my first Kawakami card, so I'll have a write-up about him once it arrives from Japan.
Regarding my "Tsubouchi" card. Turns out it is slightly too large to be JBR 37. It measures 2 and 1/8th by 2 and 3/8th inches. That's within the margin of error for JBR 74 (
approximately 2 and 3/16ths by 2 and 5/16ths). JBR 75 is listed as approx. 2 1/16th by 2 3/16ths, although I imagine late 40s Japanese baseball card production wasn't exactly a precisions affair.
I guess it could be the JBR 74 "full body" card - but the fact that there's no writing on the back tells pretty strongly against it.
The 75 card description is given as "RHB full body, end of swing, legs crossed", which is fine except that his legs aren't crossed. It also doesn't have any writing on the card (despite the description given for the JBR 75 set), on the
other hand the example card that Engel provides
also doesn't have any writing on it. So one possibility is an uncatalogued JBR 75 card; and Engel explicitly says that his list is incomplete. He says that he suspects the set has about 500 cards in it, but that he's catalogued only 209. So an uncatalogued JBR 75 card that was cut a little large sounds like a possibility.
And for anyone who is interested, I found a nice quick history of Japanese baseball
here.