I do not need the one that's milled for an adjustable slide.
I need the original one.
Short of finding one at a gunshow or shopping around, Gun Parts Corp. (ph. # 914-679-2417) list the gun, but the slide is not always available.
I would guess the cost of the slide alone would be at least half the cost of another used Mak.
I think the adjustable version was Russian and the Bulgarian, E. German, Chinese and some others were fixed sighted.