well i have completed inletting my lock and what a pain in the butt.doing the lock plate was easy,doing the internals was a chore.especially not having a router to use.hand chiseled everything.gotta be an easier way!!!
Inlet the plate then mark all screw holes and the mainspring pin though the plate.
I then drill all the screw heads to the needed depth and use a large bit for the tumbler. This will give a guide for the rest of the work.
Even with a vertical mill I still dislike doing lock internals.
If you have a good drill press with a chuck *well fixed* to the spindle and a 2 axis cross slide vise (Harbor Frieght or Northern Tool etc sell cheap imports) you can use small 2 flute end mills to machine the lock internals. I would not try to machine metal with this though.
Just make sure the drill press is well bolted down and the vise is bolted solid to the the drill press.
If you lived close to Montana I think a friend still has a step pulley Bridgeport mill for sale cheap. This is the ultimate answer.
Dan