Another consideration, is what is the distance across the flats in your stocks barrel inlet. You need a barrel the same size. Lets say the barrel inlet is for a 1" across the flats barrel and Wildman's is 7/8" it won't work in your stock. The lock is another consideration.You can have a larger lock than your lock mortise and enlarge the mortise to fit the larger lock. A lock smaller than your lock mortise won't work well for you. You could make a Damascus lock plate to fit your mortise and fit the internals from Wildman's lock to it.
Of course all this adds up to ditching your stock, buy a slab of wood and fit Wildman's barrel and lock into it properly which takes some skills.
I haven't inletted a barrel or drilled a ramrod hole yet. I send my stock blank and barrel to a guy who specializes in this kind of work and get it done to perfection instead of spending two weeks with a chisel doing it myself with questionable results.