Who cares!??
I agree, if it wern't for the filthy rich dirt bags buying up the ultra rare 100% original cars as investments, a lot of them may have already fell into the hands of people like dgc or myself and would be "gone forever" so to speak.
By that same merit if it wernt for guys like him and I, there would be even fewer yet left because I am sure many feel the same, I bought it and I can make it into what I like. If I couldn't and it were just a dd vehicle, it would be where the rest of my dd's are ( I rarely ever let a vehicle leave my hands to another owner, they all end up stripped and crushed, thats why I have a lot of parts laying around for whatever project I fancy next).
I have made (2) 4 door satelites, (2) 2 door satelites, a 74 Grand Fury, 78 Dodge Colt, a 71 Dart, a 73 Buick Opel GT, and an 82 Mazda 626 all meet the crusher (that Mazda was actually an awsome car for a ricer!) None of them (except the opel, and that was taken by an accident) were a collectible, but they supply parts for others and myself yet to this day for our more collectible (so to speak) cars.
I say do what makes you happy, if your worried about collectibilty, then hold on to original parts unitl you decide you wanna sell it and put them back if you think it will increase the value. Even altered old muscle will sell in these days of overinflatted rip-off garbage fuels prices, as an example, my 73 Dart Swinger (original /6 with auto and 7 1/4) that I have swapped in a mid 70's 360, heavily modded 904, late 50's 8 3/4 and custom backspaced 8" stock style wheels and paint that has stains, little rust bubbles in the typical spots, and strips of paint peeled away where the prior owner had glued non factory moulding to it, still gets people asking me if I will sell it or if I am interested in selling it. My answer is/has/and always will be "You can't afford what I want for it" ie I wouldn't sell it. My kids and wife like it to much so they get it when I am gone, and with any luck it will be in better shape then than now and I will have taught them how to care for and maintain it (hopefully gas will still exist then too).
In other words do whatever rings your bell man.