I have the same findings.

It should theoretically be possible to flash it to the card using a PC flasher, but it doesn't take for some reason.

The ROM chip is soldered to the board. I can take a picture of it for you if you like.

I think the file might be encoded somehow, because it seems a wee bit too big (I think it's supposed to be 128K, yet the file is actually 136K).

Yay! Progress!!

c