So while we are on the topic of replacign the old board, I thought I would take a moment to document what its specs are for posterity..
Processor - PIC16LF873-041SO
Firmware (Of processor NOT the Race program itself) - 9.8.2002
Serial Com provided by a intersil ICL3221CA (Bottom right of board)
Memory storage (settings) provided by 24LC08B (Below the silver capacitor)
4.8v Ni-MH (made up of 4x 67AAAA cells)
MicroMolex Connector (I will try to look up the PN for these).
Oddly enough it looks like the board was programmed with normal serial commands.. I know people (the 5 of us who still use Raceguns!) have been struggling recently due to a lack of programming cables/charging cables but this one looks to use a standard TTL/UART interface.. Connectors for those are cheap (search ebay for USB to UART), and then you would just need to connect the pins to the correct pins on the connector..
You COULD even build in a connector into it and make the board USB programmable! I would get one of the ones on EBAY that has the cable all made with just the pins on the end.. Plug them in the correct order and it should work just fine with the current RIP software!