I have a conundrum but I may have found a solution. I am hoping someone here has some experience. My Vigilant sits on relativley narrow hearth and so the back of the stove goes into the fireplace opening a bit. The issue I have is going from the 8" oval to get to my sheetmetal opening blocking the damper is a squeeze. For 30+ years I have used an 8" T with the short, offset 8" oval to round 8" adapter. But now, for what ever reason, all the 8" T's , 24 gauge, that I attach onto the adapter and squeezed into an oval to go up the chimney are no longer made with an attached snout. Since I have had to cut the entry pipe on the T to get it short enough to fit my opening, with the new design T's it can't be done. Anyway, I have found two possible solutions. One is I found an 8" oval to 8" round elbow which I think will fit for me, just have to fix/tweak my blockoff plate in the damper. A better solution, that I think is available is VC (0r somebody) makes a replacement collar that replaces the 8"oval outlet with a 6" round outlet. That seems like it would make my life easy, a simple solution by making everything 6" round. I have found several posts where the only down side to that approach is (supposedly) if you run the stove with wood, doors open, the exhaust might not be sufficient. Since my only burn time is coal, not an issue. Moreover, I didn't calculate the cross section area, but I don't imagine an 8" oval is dramatically larger than a round 6" exhaust.....maybe 20-25% perhaps? Anyway, here's my question: anyone ever swap the 8"oval to the 6" round? Is there really a part available for a Vigilant? I found what I beleive is the part number..... something like 1580 or p/n 0001580. Any thoughts would be greatly appreciated.