Mid 70's evinrude 75 hp.need some advice

Hoping someone can give some advice.I have the opportunity to pick up an older 16 ft.starcraft/75 evinrude in good condition for a great price.Current owner says lower cylinder has low compression but that the motor still runs decent.My question is how much to correct the cylinder issue,I believe he said the two upper cylinders are at 115 and the lower is at 30.Any ■■■■■■■■ would be greatly appreciated as this boat is exactly what I want for flounder and lake,river fishing.I also really love the older,high side walkthrough starcrafts even though they are riveted.
Many thanks.

If you realy want the boat buy it without the motor! I think a motor that old is not worth the money to rebuild! Just my thinking.

Thanks boatpoor,I’m hoping it’s just a head gasket,owner says compression loss was sudden but who knows.I have an 03 yami 60 to use if needed but I really like the classic look of the older evinrude.I had a 79 model that ran for years with no problems,it had a bad gasket after overheating.The boat/trailer is in such great shape that I believe it’s well worth the $900 selling price.