I have "customized" several of my shooter luger pistols, not harming any collecitbles in the process- and neither did you.
I have the same GT bull barrel, now in three lengths. 3.25" on my "baby, I recently changed the 5" to a 4" bull on another full size shooter. I've put a 9mm heavy barrel profile with 1900 toggle on my 1906 shooter. And a 6" 7,65mm bbl on a commercial that came to me without a barrel- but otherwise a matching pistol- still have not figured that one out!
On yours, I'd add an adjustable rear sight; and not much else I can think of, unless you want a 16" barrel and a stock.
(for those wondering what the heck is the black stuff on the 1906, it is a couple layers of "fuzzy" velcro to thicken the grip safety, my hand doesn't always press the safety fully in without a little extra thickness.
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