I'm not sure of this 100%, but since Traditions guns are not manufactured in the US, the drum threads are most likely metric. If they are, that may be your only difficulty. To make it easy to replace anywhere in the US by any good supplier (like Muzzleloader Builders Supply), drill it out and re-tap it to a 5/16-24 thread. That way, you could replace your original drum with a standard drum of the same outside diameter, with a 1/4-28 nipple thread (another standard easy to find!) and when you want to go to flint, change to a 5/16-24 slotted touch hole liner. When building interchangeables, it is always the best to build and fit the percussion first. Hope this helps!
Almost forgot your question about the flint. I believe L&R now makes what they call an RPL (replacement lock) for your rifle. Call 'em and check it out. You would need to know the model of your rifle.