Depends on models. The older models, M/46 and M46A or M/46B, use a different style. The M/640 have a ramp with 3/8" dovetailed front sight.
The older models use a smaller dovetail and enter at the front of the ramp.
As for bases and rings, I can't help much as my own rifles in these series are not d&t, but the easiest way to go is surely using Weaver bases (#55 rear and #46 front). If you want to mount the scope very low, you will sure need a safety - the easiest way to go is to install and aftermarket trigger with side safety or a new low swing lever designed for such.
As for the bolt handle, as the root of the existing handle is pretty high the way it is, you better cut it and have a new handle welded there.