The short rail CZs were the very first ones made, and relatively few have ever made it to the U.S. Short rail means just that -- rather than the rails (that containhold the slide) being the full length of the frame, the rails are shorter.
It is my understanding, perhaps incorrect, that the short rails presented a durability issue, and were lengthened later, in production guns.
For a true (high value) collectible gun, you need original box, papers, magazines, and a gun in pristine condition.
A restored, reblued, reworked gun seldom fetches anything close to what a top-quality "collectible" gun will bring. In most cases, if you had extra work done (rebluing, for example) the extra work will not, when added to purchase price, bring the owner what he or she has invested. Adds on seldom return their cost on ANY gun.
All of us are collectors, in a sense, but few of us are serious collectors intent upon building a "portfolio" of guns that will appreciate in value -- or, even if we were, would know how to do that. (I learned this by collecting some Lugers and some Mausers, over the years -- I soon found that the people who really do well, as collectors, either go only for pristine guns that meet all the criteria of "collectibles" (and are truly rare), or simply acquire and keep the guns they like with no thought to value appreciation.
On one of the C&R forums, in years past, I remember some guys who have 100+ Mosin Nagent rifles, all relatively rough, back then, and none worth much more than $50. They loved the guns and loved having a bunch of them. They were collectors, too.
The price yo've been quoted is probably way too high.
