So, long story short, I have an extra HV differential probe, a Tek P5200. It doesn't require a TekProbe interface, so it would be compatible with most scopes (contact me for more info). I just tested it with my function generator and it works great. Anyone interested in it?
If anyone else has a TekProbe interface compatible scope, I have something else that could be available for rent.... ahem, Team Extreme Testing represent!