this looks like somebody's proprietary memory and I/O expansion. the back side of the board isn't visible, the front has no gold fingers on the ISA card edge, so it's safe to conclude that it won't work with anything other than the specific motherboard it was designed for.
AFAIK, the EuroPlus are made in Ireland. A EuroPlus should also have a modified logic board (a few jumpers change)
If your logic board does not have those changes, it's possible you have a stock II Plus fitted with a EuroPlus lid.
Depends on if the board has enough sockets for 4MB, and how attached you are to that motherboard.
DIP does get rather expensive, and to reach 4MB you're talking about 36 chips.
Assuming the board is fitted with that many sockets, cost of DIP is still considerable.
If you're not emotionally...
Apple has a near compulsive obsession with leaving their mark on their "stuff."
All their prototypes (that I have seen) are silkscreened with their name, copyright notice and company logo.
What you have is without a doubt, a clone board.
sorry, it was not my intention to insinuate that you agree with the valuation. I just wanted to point out that based on the length of time they've remained unsold, the asking price is probably excessive.