Foot pegs could be played around with but I don’t think handlebars being adjustable would be easy to do. One could change the risers (mounts) to raise or shorten them a bit but that would be very limited. I note in the TV show “Mayans” every single one of those bikers are using ape hangers. Personally I don’t like them at all.
Here’s what Fonda’s bike should have looked like. Practical and functional fat bob. It’s mine and I still have it but in a different form. Slapped this together in about a week and what I like about Harleys is that items from decades apart will interchange. This one is a 1950 panhead engine, 47 transmission, 57 front forks. 56 straight leg frame, 60s Sportster front fender, 53 bobbed rear fender, 71 Shovelhead gas tanks with 69 Police Special speedometer, Triumph tail lamp, Hyster fork lift oil filter adapter, and so on. Wanted something no one else has so I cut the 8" over fork tubes down to 3 and 3/32 of an inch and rethreaded them. White thing in the middle is a Purolator oil filter.
Bone stock engine but the strongest running pan I’ve ever seen. Laid 20 feet of rubber with it one night…