Ron,
Oliver 1655 tractors (~70 HP)were manufactured back in the '70s so its about 30 years old. I bought a 1975 model and ran it for a couple years and then traded up for a bigger tractor. My neighbor then purchased it and still uses it today. Four wheel wasn't a popular option, but it is a mechancial system, a good system at the time. 11,000 is alot of hours. Most used ones I see today have 5-8000 hours. The value will depend upon condition. It could have alot more hours in it if it has been well maintained. How much does the seller want for it?
OrangeGuy
P.S. I just reread your post and saw that 11,000 referred to price not hours. I would say the price is too high unless it has very low hours (under 1500).