I managed to acquire a dump from another guy who bought from the same seller.
But it looks like it wasn't dumped right. the update tool says its version 0.0.00
I did try it though, just getting a yellow screen with hourglass icon!
but it is the only dump I have tried that has the same yellow load screen as the player originally. I opened the dump with atjupload, to find it only contains 3 files. could this be merged with another firmware maybe??
if anyone wants to take a look at it pm with email address and i will send it.