Sorry if I disagree with most here but I see no reason not to convert it. Find the largest touchhole liner available and drill/tap the barrel for it. Buy or make a suitable drum and put a new replacement touchhole liner in storage. Remove the unneeded parts from the existing lock plate and put them in storage with the liner. Convert the flint plate to percussion using a new hammer from any of the parts suppliers. Buy a new lock plate from Kibler and put it in storage too. You'll have everything you need to convert the gun back anytime you wish. The conversion will be historically accurate and won't hurt the rifle as it can be converted back whenever without much work. The end result would be like a high quality rifle that had been converted to the new ignition system circa 1840 in a manner consistent with that time. I have a very nice rifle and pistol that a friend built and I had him fit percussion locks to both so that I can change them if/when I feel like it but they probably will always remain flint.