I do not believe there is a comprehesive website or even a book that cross references reboxes, retools, reissues, etc. The very best way to find out this information is to ask multiple veteran modelers. I say multiple because every once in a while we can get something wrong.
Case in point, when Italeri released an M1A2 kit, it was shortly after they gained the old Esci molds and reissued a couple of old Esci M60 kits and some old Esci 1/72 scale armor kits. A few modelers assumed the new Italeri M1A2 kit was a reissue of the terrible old Esci Abrams kit and reported it as such. But Esci had never done an M1A2 and I had bought one after opening the box. It was a new tool kit and for a brief moment in time, it was the best Abrams kit on the market.
Another case is when Italeri reissued the old Esci M60 Blazer kit I mentioned above. Many folks reported the Italeri kit as a straight Esci repop, but it wasn't. The original Esci Blazer included all the optional parts to make that kit into a standard M60A1. The kit was a great deal; you could build an regular M60A1 and use the IDF fittings to dress up other kits. I grabbed a few when they hit the Big Lots closeout stores for a whopping $4.99.
When Italeri reissued it, they omitted all the plain M60 parts and the only left the IDF-specific version parts in the kit. You could no longer build a standard non-IDF tank out of box.