Small world. The historian mentioned was an interpreter when I started. IIRC GS-4 permanent with furlough, but might have been a 5.
I knew he had got an historian at the Arch but not what he actually worked on.
Somewhere on my computer I have my notes and references... but I'm pretty sure that those rifles that were modified for the Corps of Discovery came from the long rifles issued to the Kentucky volunteers that marched with Washington in response to the Whiskey Rebellion. They were turned in when the Kentucky troops mustered out and were stored in a local arsenal in Virginia (can't recall the name). When the Harper's Ferry Arsenal was established they were moved to HF until the were picked out and modified.