I started a thread on the subject a few weeks ago but there didn't seem to be much interest so I deleted it.
I just finished such a swap; I was putting flintlock in a percussion stock which may have made it harder but I suspect the lock plates are pretty much the same. What I found out was all TC guns are a little different, some make the swap with just inletting the lock mortise for the flintlock internals, some like me had to make some major alterations to complete the task. This leads me to believe that TC guns are the final product of whoever initially put them together at the factory, some are made more precisely than others.
Here is what I had to do to;
Remove a LOT of wood in the lock mortise to fit the lock, add wood to the lock panel to take up the sloppy fit of the undersized L&R lockplate.
Move the barrel back and down to align the touch hole with the pan. Plug and redrill the tang screw holes
Reposition the lock bolt hole so the bolt would hit the threaded part on the L&R bridal.
Grind off the tang on one side to accommodate the the lock internals and the new lock bolt hole.
Add metal to the set trigger bar so it would function properly with the L&R lock.
Sent the L&R lock back to L&R twice; the first time for a casting flaw in the lockplate and the second time because the tumbler shaft was too long and barely let the cock stop hit the top edge of the lock plate.
All said and done, it is a nice lock and enhances the TC gun immensely.
I started with a bunch of random parts;
And ended up with this;