opinions on 1990 mercruiser 3.0

[boaterntexas]

thinking of buying a new boat, it's a 1990 17' glastron sierra with a mercruiser 3.0, alpha one outdrive, and a 19p ss prop. The boat it self is in excellent condition, no floor root, upolstrey is imaculate, very few scrachtes onthe hull bottom. The motor I hear has between 50 to 75 hours, it looks great, how ever I did notice some rust on the spark plugs, our atleast where the sprak plugs meet the cylinder head, I didin't pull them to see what they look like in side. The bilge is in great shap, very very clean. no oil spils ect.. The only other thing of concern is that no maintance other tha changin the motor oil and a lower unit relube has been done to the motor in atleast 3yrs, also I notced that I oculd see what appeared to be a gasket of some sort on the outdrive, where is take its right angle turn afte comming out of the boat.. is this normall<br /><br /> Thanks for oyu adive and opinions.. THomas<br /><br /> want to add more info..<br /> SN# 764786<br /> Model mcm3.0<br /> block # 4287808<br /><br />is this motor really a 1990?