[nat]

This is Kawakami: 川上
So I'd assume that the red boarded card is Tetsuharu Kawakami, the Giants' great first baseman. He was a left-handed batter, so that checks out. The text on his right shoulder says "All Japan", so it wouldn't surprise me if this card was issued in conjunction with one of the American tours. (The Seals' 1949 tour seems likely, but that's just a guess.)

This is Oh: 王
So the 1970s-looking menko is probably Sadaharu Oh.

Fumio Fujimura, the Tigers' great, was not a catcher. He was mostly a 3B/1B kind of guy, also playing some 2B, OF, and began his career as a pitcher. But he never caught a game. So that's not him. He's not the guy at bat either, since he was right handed.

As for the double card with Nagashima - I don't recognize the set. Many sets had backs similar to that one, but all of the ones that I can think of have writing on the front of the card. It could be from an uncatalogued set - there are lots of them out their - but I don't have my copy of Engel handy to check.