A number of years ago I asked Briley's to do the same thing for me on a VERY nice pre war Merkel 16 gauge S x S that also had no choke at all in the left barrel. I called and talked to them, specified particularly that I wanted a permanent and INVISIBLE tube installed to give me some choke in the second barrel for pheasant hunting, right barrel already was bored IC, so it was o.k. I particularly emphasized that I wanted an invisible completed job, not simply a choke tube screwed in. It came back to me with an off-the-shelf choke tube installed that I could unscrew easily, and had a recess cut at the beginning of the choke that was very visible. I had to send it back twice before they finally did the job I wanted. They kept the gun tied up for about 9 months total, and when it came back there was a large deep scratch on the outside of the left barrel apparently from some holding jig. To be sure, they finally got the job right except for the large scratch, which required a new rust blue job after I got it back at my expense. They ended up refunding the money I paid for the tube installation, but I had to pay for the reblue, so overall I got value for what I paid for, I suppose, but I won't go back to Briley's again. I have had good luck with Seminole in Florida in the past, but haven't used them lately.