Hard to say what is "best" but I have stuff off all of my bikes I should have done with what the HD shops do with most of it, Dumpster city.
Our take-offs are certainly better than the stock stuff, but I don't see myself converting back to stock at anytime. While I have it, I want it the way I have it and when I sell it I won't need any of the adds I have on it. If you keep it, put it in a big box, mark it well and don't froget you have it when you sell it.
But for my part, anyone interested in a stock SERK, SEEG, SEUC or whatever will be looking for one with no or low miles and not my well ridden bike.
Bikes just don't seem to be like cars, but I guess if I had a stock 47 HD of somekind, it would be cool. These later CVO bikes in large numbers may not hold nearly the value that a low volume earlier one would however.
I already sold my black POS starter to B B when I got the chrome one, slip ons to another friend, headlight too. Rebuilt the stock seat and tossed the small backrest for a bigger one so it's done for, I guess I'm a seller.