Hi,
Has the hole pattern for handles on KH saddles changed at all over the years or has it remained the same since the original saddles were manufactured?
Thanks,
I had a KH Fusion saddle from 2004 or 2005, and it had the KH Velo base that was use until 2009. I have a couple of more recent Fusion Street Saddles (new base with bolts), as well as a 2008 Fusion Freeride, and they all have the same bolt pattern for the grip. The rear bumper fits differently between the two bases though.
Actually now that I think about it they only make one mount for the T-Bar, and that fits all of the saddles (the stiffener plate is a different matter though).
I no longer have my 2005 Muni saddle at hand to re-verify but as far as I remember the front handle bolt pattern have not changed (the handle got modified). The best clue is the brake lever bracket that is still the same 
The main source of incompatible changes happened to the rear bumper (way more dependent on the base generation).
Thank you for your thorough responses.