nice easy motors to work on...
1- change impeller
2-check gear oil and replace use new washers to seal properly
3- won't hurt to clean the carb passages with carb cleaner ...DO NOT put carb cleaner on the float !! if float crumbles ...replace it
4- remove the pump cover and inspect the small screen ...clean if need be
ignition coils may be all cracked if never replaced you need to pull the flywheel (you will need a puller )
50 year old condensers are likely in need of replacement
while under the FW .. clean points with ex; 300 grit paper check for a gap of .020 at the high point of the cam for now
may as well put in new j6c plugs
see links for basic maintenance o small outboards
[URL='http://www.leeroysramblings.com/johnson_magneto.htm']Johnson (leeroysramblings.com)
and UTUBE is your friend with good videos