1979 MERCURY 80hp ALTERNATOR???

[AGUILERA2000]

Hi guys, i just bought me a 1979 800 mercury 80hp outboard. excellent runner, smooth, powerful, great. well, i want to keep it that way for a while. WHAT DO I NEED TO DO? THE BASICS... OIL CHANCE, LOWER UNIT OIL, GAS MIX 50:1, WHAT ELSE???????
And does this motor have an alternator???
P.S. what is the rough value of this motor working in excellent condition? did i pay to much?
thank you