So I need to do the sacreligious and swap out a bunch of original parts on a 65 Coppertone. It currently has a Shimano Nexus 3 speed hub to give it a little extra go, but everything else is pretty rickety at this point, so I am going to modernize. Any advice appreciated, I am definitely thinking of converting to a 3 piece crank, new chain of course, and probably new rims. Going to add some sky-hi apes too to make it a beach bike. The two things I am stuck on are whether it is worth trying to swap out to a threadless stem/forks, and also what gearing ratio I should use (I know nothing about this). It is mostly going to be used on flat ground, so chill and easy is the goal, but also with some oomph to get up boardwalk ramps or small hills.