My set up isn't wired yet..... but the vehicle was already going to need pretty much every wire replaced and most of the electrical pieces are under scrutiny whether they work (exposed to the elements for the better part of 30 years).
With that in mind - I went searching for an original 1970 turn signal/brake diagram.... it's overly complicated. I believe it uses a 6 wire system (most these days use 4, 5, or 7), runs through the hazaard switch first, then through the hazaard flasher, then through the brake switch, then through the turn signal flasher, I believe there was 1 or 2 other components.... I also faintly recall most of the wire colors on the turn signal cam switch being pretty much the same...
I decided to go with a univeral 'hot rod' style turn signal cam... picked one up on ebay for like $50-60... it comes with (only needs) 1 heavy duty flasher set up for LED's and has a hazaard switch built in. The diagram comes with the specific set up to use front turn signals independently from the rear combination brake/turn. In wiring all of my tail lights (which is all I've done on the frame wiring wise so far) all I had to run was:
Running light
Left brake/turn
Right brake/turn
reverse
The front turn signals will have a separate output. Simple, to the point, and easy to diagnose/fix if ever goes wrong.