"I probably should just buy and use it as is,.."
You've just hit the nail squarely on the head(!)
.. with a couple of provisos; one, that the Poly Choke is on straight; two, that the gun is marked for 2&3/4" ammunition. Early 16ga. model 12's were 2 & 9/16" chambered and had short ejection ports making reliable ejection of a 2& 3/4" hull problematic. Many got the ejection ports opened up by milling and had their receivers reblued. Nothing wrong with unmodified original early guns at all, if you use a hull length that is suitable. They are perfectly capable of handling modern US spec ammunition.
FWIW, you are not likely to get any better patterns from a screw in or fixed choke than you can from a Polly Choke and the cost to pursue the asthetic you desire exceeds any probable ROI. If you are looking at the intended target, you will never notice the PC. They are kinda fun actually, especially on a sporting Clays course where you can just 'dial' to your heart's content and watch others develop what only could be called a type of 'choke envy' as they fumble about with wrenches and tubes and such. Most PC equipt'd guns get discounted accordingly and that should work even further to your advantage. Set the angst aside and just go buy it!
