If you have the early and late carbs on your bench together, you might be able to glean the differences. The physical length of the slide changed on the later ones, as did the hole size that pulls the vacuum for the diaphragm. There was a brief time when the early and later carbs "kitbashed", and some of each parts were found in the other. You will immediately know if the slides are right, because they won't cross between them, but if you have later carbs, see if you can adjust the hole (orifice) size in the downstream side of the carb, near the butterfly, to match the hole size in your earlier carbs. This will quicken the lift. But, the later slides don't open as far, and there's not much you can do about that part.
I've repaired (and replaced) an awful lot of those diaphragms. With some thin sheet rubber and some Pliobond glue, you can make a set last quite a long while by gluing long, thin, narrow strip patches over the cracks. Try to go from outside edge to the center, so it will flex like the rest of the diaphragm. If you go circumferentially, it will stiffen the diaphragm and overdampen the slide, making it boggy and rich-running.
