"Owner states it ready to roll " famous last words. While I know it's tempting to ride it back that far without a thorough check, I wouldn't do it or suggest it. Many of these are now starting to have pump problems and or fuel filter problems just from age. While I find them to be very dependable bikes, you don't know this bike or the owner.
The most notorious problem is the battery, these bikes take a lot of juice to turn over and if the battery isn't 100% it could be trip breaker also you have to make sure all of the grounds are clean no matter how they visually look, then apply an anti-corrossive.
If as you say the owner was meticulous, then it should come with the owners manual and the tool set.
Check the oil level, warmed up and on the side stand, Do Not Over Fill it ! Big headaches if you do.
Check your tire pressure, the usual stuff.
Check the drive belt and pulleys.
Check the wear on the tires, that it's relatively even, no cracks on the rims
Check the trip!e tree bearings for excessive play.
" " clutch and lever for proper adjustments.
You want it stone cold when you arrive, should start smoothly, might be a slight pause due to compression stroke. Should idle smoothly and when you test ride it, it should shift pretty smoothly.
I'm sure there are other things that I might have forgotten but I'm sure others will pitch in .
Good luck.
Make sure it was never down, tell tale signs, scrapes on low hanging parts.