I have a pre WWI Merkel S x S 16 gauge that had the same situation of the chokes having been opened at some time in the past to dimensions that did not suit me. At least the left barrel did not, the right still had IC choke, which was o.k. for our southern walk-up bird shooting. I wanted the left barrel to be about Modified, so I called Brileys and talked to them about the job. I asked for an "invisible" permanent sleeve to be installed in the left tube only to give me that degree of choke. The guy I spoke with said it would be "no problem," they did it all the time, send the barrels to him. Well, to cut to the end of the story, after a much longer time period than they promised, they came back and it appeared they had threaded that barrel and simply installed an off the shelf choke tube in it, very visible, not at all what I had asked for. I called and asked for the same guy, told him what I had received back, he said send it back and he would see that it was done correctly this time. Well, it took another 4 months or so, but they did it right this time. I'm not sure how the sleeve is actually installed, perhaps either soldered in or maybe even some super adhesive, but it is invisible, and the gun now has about 8 thousandths right and 18 thousandths left, which suits my needs fine. I have shot it hundreds of rounds since that time (about 12 or 13 years now) and the sleeve is still in place and I am pleased with it. So, Brileys can do the work, but I would be very clear with them about what you want done, so hopefully they get it right the first time.
