I don't see any identifying marks to tell the manufacturer but the card with the chip labeled "HD6845R" is almost certainly an 80 column video card. It's a different layout from my Videx Videoterm but it has essentially the same components.
Actually, I stand corrected; your card is almost identical to a Videx Videoterm, it's just missing the silkscreen in the corner and there are a few component changes. I wonder if it's some kind of knockoff. (Such things were not rare in the Apple II Plus' day; in fact, my Apple II Plus is a real Apple motherboard in the case of a clone; the original Clone board is alas lost to history but it was nearly trace-for-trace identical to the real one.)
