[Elecraft] K2 new builder (maybe) need historical info

[Martin Sole]

Dear all,

I have been offered an unbuilt K2 kit. So far as I know it is somewhere 
in the 3000 series of serial numbers, maybe around 3500 if I remember 
what the guy said. I am interested to know how far this would differ 
from the latest radio and what steps I might need to take to ensure peak 
performance and compatibility, if any. Can I buy an upgrade kit to the 
latest version?

I will save about $100 on a current K2 kit price, not sure if that 
represents value for the vintage or not.

Thoughts and opinions appreciated.

Thanks,
Martin, HS0ZED