You may want to check with the previous owner and see if it has the "High Precision Worm", from memory it came out about then.
As far as the Gemini is concerned, is it fitted with a Gemini unit???, they had to be specified or is it a stepper motor version.
If it has a Gemini fitted, should be about Version 3.13, mine originally was a V 3, I just got a new EPROM from the US, about $25 + postage I think, Thomas Hilton:
http://www.astronomystores.net/store/ is probably one of the best for replacement bits and cables etc. Just take the old EPROM out and pop in a new one and your updated.
Failing that, a Gemini unit is about $1500 +, been a while since I have priced one
, something you don't buy everyday
Welcome to the world of G-11's, you'll be an expert in no time.
Cheers
JohnG