Even though I support the general idea of this, we gotta make sure it still makes sense. Combining an Uz-I with a Colt. 45 to get an Mp5k makes no sense at all as the Colt. 45 uses completely different bullets and wouldn't help improve the Uzi in any way.
But if you were for example going to craft a Chrome Shotgun in combination with Molotov Cocktails, you could get yourself a Flamethrower as the pressure a shotgun brings you in combination with a Molotov bottle would get you the right result.
As in, the dev team will have to find many realistic ways for this to be used before we can consider adding this kinda thing to the server, and definitely should try to keep it balanced.