Post surgery report....
Looking for more info on the Peterson kit I found this:
http://www.thenakedastronomer.com/pa...p#.Xq0pw8YRXm8
Which has really good instructions on the teardown procedure.
I had to tighten one of the bolts holding the worm train, and a small amount of end float on the worm itself. The only play is now in the meshing of the worm and the spur gear so hopefully after I also re trained the drives it should track a bit better.
The nice surprise was that it looks like the previous owner had installed a Peterson kit!
Thanks again Philip for pointing me in the right direction!