Congrats on getting the shotgun verified as an O'Connor gun. Getting a written verification many times can be difficult in my research experience.
I got in a 270 Win barrel for a Rem 700 BDL to put together a custom 270 rifle build for myself. Alas, a friend whom did me a favor previously, needed a 270 Win for his son for a Christmas gift and could not find a 270 anywhere, seems like FL and the 270 do not match up too well. So I built the custom 270, I had in mind for me, for him as a gift for his son. He only needed it finished in 12 days. It shot a sub 1/2" group on the function test. He got the rifle and group, for the box, The only 270 Win I ever owned, if only for a day.