With respect to quill tension, most full size mills like the Bridgeport and the First mills are designed to "balance" the quill. They should not return or drop. They should stay where they are put. Hope that helps!
This is exactly how my First LC 1-1/2 operates. @grease monkey, is your First an LC 1-1/2?
BTW for Bridgeport machines as well as the clones like a First or a Hartford, H & W Machine Repair is a great source for disassembly and repair info. They have produced a series of very good videos showing step by step tear down and build up of both step drive and variable speed machines.
D
