According to India's Enfields, the butt stamp T-D-E was placed on a number of different marks of rifles, but not the .410 musket. That wood should be marked S ^ A (over) I.
Interesting low serial number. Looks like a nice little musket. Verify that it's for a 2-1/2" .410, not the 3". They started life as a .303 "grape shot" for loss of the correct term,
and many were reamed to take the .410. Check the barrel for any signs of demil before shooting.