If you cannot get it to boot with a 2.0 image then you might also want to try adding the "runideturbo=false" to the bootparams. The bootloop can also be caused by using a non-quantum drive with a 2.0 kernel and not having ideturbo turned off.
If the above fails, the prom is probably messed up. I would be willing to purchase the unit from you because I have the facilities to remove the prom, reprogram it with my Data I/O, and then solder it back on. PM me if you are still interested in selling it.
Information wants to be free....