Well I'm slowly gathering the needed stuff to weld them here at home and have the parts made up local. I haven't done enough leg work to have a cost yet on welded aluminum units. The cast is WAY out of sight, all foundry's require a cad drawing, their mold maker to make the molds, etc etc... minimum of 50 sets, then their machine shop to do the milling... the smallest guesstimate I got was 30-40K ... Not in my wheel house for cast covers...
BUT beings I am a fabricator by trade the welded units are more in my wheel house so I'm working that way for covers & intakes... but still not a lot of folks would spend X amount when a cover on fleebay is 30$...