Ken,
if you indeed do decide to go back, I think we should all collectively start making a list of questions to ask the seller. The way I try to place value on a car I'm interested in is to know first off what that car would be worth in A-1 shape......then start subtracting for the cost to get it to that condition; then that's my offer. Not an exact science of course, but it has served me well over the years, since many sellers post a price based on emotion rather than fact.
So my questions would begin:
1) When, if ever, were the tires replaced? Anything over 6-7 years max, they gotta go.
2) Have the brakes been rebuilt/had fluid flushed since new? Old original brake fluid will ruin brake calipers/master cylinders. Also, are calipers sleeved with stainless or not.
3) Hoses and belts original? If so, gotta go.
4) All fluids flushed? If not, a definite must.
5) All rubber bushings, seals checked for rot. These cars leak like sieves if not exercised.
My biggest concern relates to your mentioning the seller stating he did all his own maintenance. I say this because not everyone keeps meticulous records relating to dates and mileage........when it comes to buying a used car, no offense, but I trust no ones word.......show me proof, don't tell me.
In pristine shape, in my mind that car is worth maybe $17,000 - $18,000. The powertrain is a favoured choice, but holds a premium of maybe $1500 - if in good shape. Blue smoke on startup on a 30,000km engine is concerning.
I'm sure our friends will add to your checklist here. One last thing. LOTS OF PICS, and leave your checkbook at home - 24 hours to sleep on your decision is never a bad thing.
Good Luck