Assembled but w/o mu-meter dial test indicator, showing the brass "travel lock" (and hinge bolt hole: left) in the base plate - push from right side to release, from left to lock arm to base. Differential screw drilled and tapped for M4 Allen bolt for meter fine adjustment. Only one each of 3 & 4 mm Allen keys needed for operation as well as its entire disassembly, as the anvil and its lock nut isn't really needed for coarse adjust, as that gets done when mounting the DTI.