what changed with spur 20000 ?

[rhodes2010]

So I held off purchasing a 1987 Spur with serial number 16xxx after
reading of the significant changes in 1987 1/2 and serial numbers 20000
and above.

Can anyone be a little more specific about the electrical changes/upgrades made ?

A second question is:
I am looking to buy my first RR, I plan I doing all maintanance myself.
My expectation is to drive it often, at least 20,000 miles per year.
I live in Southern California. Can anyone recommend a particular sereies/model/years ?
I always thought I would end up with a 1970's model, but these 1980's seem to be a very good value.

Again, I want something I can maintain (using all the proper equipment of course).