The question is a good one -- as the pre-B CZ-75 has a totally different dovetail/sight mount system than newer CZs, and it's almost impossible to find a after-market sights that will work without adjusting the gun. I've had several pre-Bs, and the small rear sight is not one of the gun's better features.
The OP's bet might be to contact the CZ Custom Shop and see what they'd charge to recut the dovetail and install one of the sights they offer. He might also consider a new front sight, while you're at it -- it's probably "staked" and not dovetailed. See what they have for that "problem."
(It's unlikely that a typical pre-B will ever be much of a collectible, so changing the sight system and altering the slide isn't going to affect value; it might actually help resale value, if you ever sell. There are a LOT of pre-Bs around, and many more in Europe and elsewhere; the short-rail models are different and you want that gun to be as close to stock as possible and unfired to retain the greatest value.)
Note: you can mail the slide to them using regular mail (as the slide is not considered a firearm, and it's legal to do so), and the shipping cost will be quite reasonable. Just be sure to insure it for several hundred $, and use Priority Mail,etc. The prepaid box will probably let you send it for less than $5, plus insurance.