The only way to mount a scope on an A1 is to drill and tap the receiver. Weaver makes a base that is close to the correct contour, so all you need is a gunsmith or machinist to drill and tap the 6-48 holes to match.
The cost for this generally runs about $40-$60 depending on who does it.
I don't know of a scope mount specifically for the receiver sight holes. Probably the most common way to mount a scope in the year your A1 was new was to use a Williams or Weaver side mount. There was a Weaver detachable side mount that was quite popular for 22's, and can often be found used at gun shows for a very modest price. You would need someone to drill & tap your 22, of course. If you were looking to retain a 'vintage' look, you could also get an old Weaver B6 scope which would fit right in with your rifle. You could also go to a gun shop and try modern scope mounts until you found one that fit the radius of your receiver, then use whatever scope suits your fancy.
If you like the vintage look idea, I could send you some images from early 50's Gun Digests.