Mid 80’s 60 hp mercury on hobie powerskiff, need parts, ignition switch, etc

[Liledgy1]

My sons just purchased a 1986 hobie power skiff with a 60 hp mercury 3 cylinder. Hasn’t been ran in a few years but the owner said it had compression, etc. Anyway, the key switch is gone, battery cables (and accessorie cables) are all same color. I need to purchase proper ignition switch, battery, fuel filter, plugs, etc. Can someone here recommend the proper switch for this motor? Serial # A197512, I believe it’s a 1986. Any other parts that should be changed? Best source? I’ll put a continuity tester on the battery leads, hopefully I can identify the cables. Thanks in advance.