RE: Old Bows
I have several Bear bows from the 50's all great shooting bow.
It depends on each bow and the treatment it has had through its life. Check it out real well.
A quality built bow like the old Bear bows are usualy fine if they haven't been abused.
Check for cracks. Test draw it and listen to it until you are comfortable.
As for your draw wieght if you can go with a lighter bow. Maybe 50 lbs or less. Shoot it untill your getting good with it and then go up in wieght. Starting with 70 lbs or near that will only create bad habits that are hard to reverse. Shoot alot with a lighter bow and concentrate on form rather than acurace, that will come with time.
Most of all just have fun at it. Thats one thing about trad its alot of fun to fling arrows.