I bought a new one in 1975. The electric start was worthless, at the time it was more of an electric assist. I would usually have to give it a kick and hit the electric start at the same time. Then it would turn over the engine. I removed the starter and blanked it off. I understand there are aftermarket starters that will now actually work.
I loved the bike, for its time it was a beast. I did several 1500+ mile trips on it. It took me from San Diego to Sturgis in 1975. Even now, with all of the refinements made in bikes, if I could find one in decent shape at a reasonable price I would be tempted to purchase it.
The biggest problem I had was with the Amal carbs, if I gained a lot of elevation I would need to pull over and adjust them, they were normally set up for sea level. It wasn't a big deal. Between that and just making it more civilized in traffic I changed out the dual Amals for a single Mikuni carb. I was fortunate to have a great British bike mechanic down the street, Sonny Angel, so he helped quite a bit it helping with the changes.
I say go for it, there are still a lot of parts available and you will have one of the iconic British bikes.
bob