Over the years, like most companies, T/C has made improvements to just about every component that goes into the making of their lock assemblies. As a result a true 1970's vintage lock has had improvements on many parts like tumblers, springs, hammers, frizzens, the geometry, etc.
For the Flintlock ignition improvements in general, T/C's late '90s redesigned Flint lock includes a hammer that is both taller and has a different angle of attack...and a different Frizzen.
Those improvements along with the improved vent liner completely rejuvenated T/C's Flintlock reliability since then.
Where flints used to have short flint life and often shatter because of the old style hammer's too square / straight on delivery into the frizzen...as well as quickly eating a horizontal groove across the frizzen face...they no longer shatter and with the new style lock, it's not uncommon to shoot a couple of 50 shot range sessions on the same flint, where previously the flint life often averaged 20-25 shots in old style locks.
OLD STYLE T/C FLINT LOCK ASSEMBLY
Note severe "S" shape to hammer, and the "notch" in the outside edge of the hammer at about 12 o'clock right above the hammer mounting screw.
Also note that the old style hammer is quite short with the bottom jaw just barely clearing the fence...and the frizzen is case colored.
NEW STYLE T/C FLINT LOCK ASSEMBLY
Note the much more gentle "S" curve shape (and no notch), it’s much taller with the lower jaw clearing much higher above the fence, the frizzen is solid jet black color.
3/4" wide x 7/8" long Tom Fuller black English flints worked best for me on these medium sized locks of several I tried, averaging 60-80 shots rarely knapping, and more if they're knapped as they wear.