Nice to hear you have one of the old 225 tms and lars you can have a chat with Tim Brown of Seaworks in New Zealand as he runs the same as you .
You should be able to pick one up via Deep Search as many companys are clearing out the yards from the good old days of 225s .
Web: http://www.m-are.com
You could use short wire jumpers of the maximum wire size that will fit in the terminals where the resistors were connected, but it is better to remove the brush holders etc. and fasten short bus bars across the through bore slip rings. If you leave the brushes and they spark, the VFD might have a problem.