OK Gang, here's the way I see it from here!
20Cows, correct me if I am going astray!
(1) I place an order with Dixie Gun Works for (1) replacement CVA bolster (P/N NP0905) with 10 X 1.25 mm threads and (3) SS vents (P/N NP0506) with 5/16 X 24 threads.
(2) I unscrew my bolster/drum from the barrel of my CVA Hawken and drill through the original cleanout hole and rethread it with a 10 X 1.25 mm tap.
(3) I cut the bolster for a length that will be slightly above the barrel flat when it is screwed into the barrel.
(4) I Cut a slot across the face of the cut off bolster to facilitate the replacement of the bolster into the barrel. The bolster is about 1/2 inch in diameter, so that a special wide blade will be needed. (need to match the slot width to the thickness of the blade).
(5) I Screw the bolster plug firmly into the barrel and carefully grind the plug flush with the barrel.
(6) I chase the threads in the plug with the 10 X 1.25 mm tap to insure that the threads are smooth.
(7) I insert the flash hole liner.
(8) I order a CVA replacement Flint Lock from Deer Creek (P/N LK1330).
(9) I install the lock and I now have a CVA Flintlock Hawken, a spare perc bolster and some spare flash hole liners in case I screw up!