(edit) You beat me to it, but I may as well post this now i've written it!
There's a few 'issues' there which the OP hasn't mentioned...that driveside rear dropout is distorted, and it looks like the forks are bent backwards above the crown. If that's the case, then it may be impossible to have a smooth turning headset. You might want to check for 'ripples' on the underside of the toptube and downtube, which would indicate that the frame has also absorbed some of the force of whatever impact bent the forks. So, all that is potentially dangerous.. Your call as to whether you can trust it or not!
Given your intended purpose for the bike, it's difficult to say whether it makes economic sense to get the frame repaired. Also would be a shame to completely strip original paint, (some of
) which has survived 46 years so far. You could perhaps clean up any rust, and then 'patch up' the paint in any colour you choose, leaving the original paint where it survives intact. For me that would be a brush job rather than a spray job. That would both prevent further corrosion, and have the advantage of making the bike look tatty and not worth nicking. Functional paint!
Looks like the original tubing decal could have been either one of these: