Welcome to the PGCA Forum Vincent- if you care to join the PGCA, IMO- it will be the best $40 you'll spend this year- the quarterly Parker Pages is well worth that- and as a paid member you can access the swap and also for sale sections of the Forum.
I have read all the posts- all good answers- I can't speak for cut down barrels, as I have never owned any double so altered (at least YET) but a re-assembled Parker 12 bore, whether ejector or extractor gun, is not all that rare.
If we were talking about a very high grade Parker with such "swapped out components", of course that factor would affect the collector value- but on the "meat and potatoes" Parkers- the 12 gauges mainly, VH(E) up through possible DH(E) that you want for either SC or field bird hunting, there is no problem with a mis-matched gun if it functions and fits you, again, IMO.
Mr. Turnbull was a guest at the Vintagers this past Sept (according to the fine write-up in Parker Pages) and he gave seminars on the proper way to field strip a Parker for cleaning, etc. He and the DelGrego family are certainly fine folks to entrust your Parker(s) to, whether a Trojan grade or an AAHE-and all points in between.
I can't speak on barrel regulation, none of my side-by-sides in my "working battery" have ever had choke or chamber re-work- BUT I am mainly a pass shooter, and like my hero the late T. Nash Buckingham, I use 12 gauges 99% of the time- and loner barrels and tighter chokes- works for me, may not for you. I like to see a bird crumple in the air, feathers hanging in the wind-before it drops dead as a graveyard headstone--I get that effect (and save my Lab a lot of cripple chasing I hope) with a snugger choked 12 bore-
I did find that for SC (and fine for quail and grouse I'd guess) 12 LC Smith Ideal with 26" barrels and choked Imp. Cyl. and Mod. (it came with the yellow factory tag matching the serial number- chokes were specified and it was made in 1945--gives me an edge (and I need all of them I can beg, borrow or steal) on sporting clays in the side-by-side events- BUT I am way far more serious about real birds (crows and barn pigeons) than I could ever get about clays- something about "teaching an old dog new tricks" I'd wager-
Anyway, Happy Holidays and please treat yourself to a annual membership in the PGCA- you won't regret it--
