It currently has 37,000 miles and has had oil changes like the book said. Its always been synthetic oil. I'm curious, as long as i take care of it, how much longer does it have?
You should be able to get a good 80,000 mikes out of it before it needs new rings and a top end job. Many last well over 100,000 miles when ridden and maintained with care.
If you REALLY take care of it, I would estimate about 20 - 25 years ! I have had 13 H-Ds in the past 50 yrs.. I still have a 1970 Sportster, That I bought new ! ( Plus 2 others ) ! You might have to overhaul it once, or twice, in the next 20 yrs..