Simmons actually put ribs on for Winchester.. many years ago.. Those factory sold were not marked.. Many people sent their barrels to Simmons over the years for ribs to be added.. The 3 that I have are all Simmons ribs..and not for sale at this time..
I have some extra model 50 barrels. I will check them out tonight and let you know what I have for sale. Do you want 12 or 20 gauge barrels? I think I also have some extra parts. Will answer tomorrow, after I locate them.
I'll check also, I have 15 Model 50's and more barrels and parts then I know what to do with. Just an FYI, I have one that I'm not selling that had a VR put on by Poly-Choke. It was a very clean installation, so I called them about it and I think they quoted 150, maybe worth checking out. Also try out http://www.corsonsbarrels.com/index.html or http://www.gunpartscorp.com/
I checked my model 50 barrels and I do not plan on selling my vent rib barrels. I do have some odd barrels that I might consider selling. Have some plain fixed choke (no rib), some plain barrels with adjustable Poly Choke. Two with Cutts (one plain, one vent rib) a 22" cyl and a 24" cyl with front and rear iron sights. I also have a couple of model 59 barrels.
If you want, you can still shoot Skeet with a Cutts, but be prepared for the wrath of your squad mates. Years ago, I used to shoot skeet with the vent rib barrel with the Cutts and a spreader tube. Kind of noisy, but really breaks targets.