I've gone the Williams cottered crank route with my '53 Sun Wasp project. The cotter press from Mike Stronich at Bikesmithdesign makes working on cottered cranks a piece of cake (if you get the quality cotter pins, which he also sells - very recommended). I bought the press originally to work on my old English three-speeds, and eventually a few colleagues' cottered crank equipped bikes as well. It pays for itself in saved time, avoided angry outbursts, tool throwing, etc. Have fun.
https://www.bikesmithdesign.com/CotterPress/