I'd consider another gori or swm, better value than many other bikes of a similar age, and still very competative.
Lothian trials club have a trial this Sunday out past Gifford, worth a look of you have the time.
Any bike can enter, but the classic championship is pre65, twin shocks and air cooled mono - with a and b routes. All other bikes are in separate results.
I'm assuming you got that from Old Knobblies ? I heated and bent mine to suit, plus ground the frame marginally as required. I also tapped the head and fitted a decompressor to ease over tdc. This takes a huge amount of the effort out of starting.
Bear in mind some / all this corrosion may be due to your engine acting as a sacrificial anode, so it is equally important to make sure the frame is rust free and painted.