John,
I'm going to do the soak in instant coffee for the Damascus following the ferric chl. and then finish with a nitre blue.  I've never tried to CC Damascus or should I say with any good results - I included a small piece once with a carbon pack and even at the sub-critical temps I case at - I had serious distortion - enough I barely recognized my sample scrap.  Maybe someone has had different results but I haven't been interested in trying it on something I have considerable time in.  A real light brown/blue from nitre looks good to me.  A real dark finish on the maple is what I'm chasing but I'm really procrastinating on the wood work.
Bluesman,
That's real close to the design I have in mind for my sear spring, thanks for sharing the pic.
   
I contemplated a cut like Winchester did their hammer fly for the fly in my tumbler but the more I drew and sketched it,  I discovered the cut a round cutter made wouldn't be feasible - thus the reason Sharps come in from the side and pin the fly from the inside...? Anyone try a different approach here? 

Chuckster, 
When you did double sets on your trapdoor what approach did you use for the fly?

It appears the two back screws are not domed and more appealing to the eye than the front two. Which of the two would be the more original to the lock and is there a reason why they are different?

The screws that hold the bridle have a small chamfer, maybe .020" while the one the sear rides on is a temporary fit while I decide whether to remove the head or finish it up...They are all 5-40 and it helps me avoid mixing them up when taking it apart etc.

The screws are let into the bridle .050" rather than try to do a counterbore which I would screw up, easier to just drop and end mill onto the bridle. The sear spring in that pic was a temp also while figuring out the proper one.As to the heat treat....I guess only time will tell , I dunk them in the lead pot to avoid overheating .

I imagine I will try to pretty things up in there before all is said and done.Like Chuck says, lockwork is a whole 'nother planet and I have been lucky so far....