I own a 1974 and lets start with is it slow... well any car that goes 55mph stock in first gear really can't be called slow now compared to the higher compression motors 1971-72 maybe but trust me by 1974 some other refinements were made that offset the minimal speed loss. Now as for the wing if you take it off as stated before welding filling and repainting. I like the looks of my recently added wing I will not go back but to each his/her own. As for the bumpers I also like the look of the ft bumper plus the areo downforce it gives at high speeds but that is just me. Here are some pictures of the ft of my car before paint once you pull the bumper off it is not hard to do there are some real little screws/ bolts and nuts that have to come off in order to get the bumper off. Ask questions there are no jerks here plenty of people to answer all questions (please nobody setup to the plate to prove me wrong
at least in 11 years nobody has been one to me.)