new to site. I'll have tons of questions

[wowiloveboats]

OK I have 17 outboards. I have a bass boat. This site rocks and I'm sure it will be very helpful...starring out. OK I am looking into buying a 1977 Mercury 850 I have a earlier 50hp mercury 500 maybe 73? 71 . I have no complete controls. Mine were taken apart and was given to me with a box of other random parts with 2 more controls in pieces... I need controls will the 77 controls and wiring fit my 73? 500. Or do you know what year or sizes would fit? Also I have to know what motors I can swap parts . Mostly motorheads and lower units...on the 500..I'll post more later about other stuff unless I can just call someone 816-973-8834 contact please...thanks I boats and there members