'71-'73 Dart Tail Light Housing ?s

A buddy of mine (with a '71, '72 and/or '73 Dart Swinger) wants to cut the REVERSE lamp portions of his tail light housings off and weld(?) a second set of BRAKE/TAIL lamp housings in their place. He's already scored a 2nd set of housings and BRAKE/TAIL lamp lenses and housings. Can the material used on the 1971 to 1973 Dart tail light housings be welded? I assume the lense openings (BRAKE/TAIL vs. REVERSE) in the bumpers are the same size? Will he have clearance issues (assuming he gets the spacing correct) mounting on them on the car? Plans are to parallel wire the BRAKE/TAIL wiring to each. Anyone ever try/done this? Any advice?