I'd leave it as a .22 also.
Sounds like it shoots perfectly as a 22 and besides , shooting that slim little rifle in 303 can't be too pleasent.

The high mounting of the scope wouldn't bother me especially on a .22.
But the base being left attached on the bbl when the scope was dismounted would.
It would really take away from the nice lines of the orig rifle.
So I'd leave the Kahles off, but then I'm not much of a scope guy anyway.

Beautiful little rifle.