Hello all, looking at buying a mid 80's b100 long shaft honda 4 stroke, he wrote Honda outboard model b100 in good condition long shaft 20" with new oil sensor, new water impeller, new head gasket, new termoosthat and new gasket. He said it runs great, he ran it at mid rpm in a large tank for about an hour with no issues, he wants like 650.00 bucks, is this a good price, ser # looks to be 1002003, Thanks...any help will be appreciated