If you want to depreciate the value of a vintage Model 21, just go ahead and jack with the original chokes.
If you are catering to the collector's value limitations based on originality, you are not going to get much use or enjoyment out of your Model 21. If you buy a Model 21 to put in the safe, pull out on occasion to admire and roll around in your hands or show off to someone who you're trying to impress with your savvy collecting prowess,by all means protect its originality with your last breath.
No one who wants a 21 to use and enjoy should hack it up in some weird way, but altering impossibly tight chokes or having Briley Thinwalls installed to suit your game is not a crime in my book. What would be a crime would be having said work done by some curmudgeon "gunsmith" that botches everything he touches.
JR
