The guy I bought my lower fairing from yesterday had just sold the '92 he had owned from new, a non oil burner with perfect compressions and 211,000 on the clock. A fellow mechanic, running his own workshop for the last 20 years, we discussed FJ's and general mechanics at length.
For what it's worth, his formula for longevity was: never idle it to warm it up.
no short trips
Oil change every 3000 (lucky him, he has it in bulk on site)
Keep it out of the sun where possible
I think the oil change intervals may be excessive but I agree 100% with the others.
Noel