Have an old Delta benchtop 8" drill press, Model 11-950, type 2. Lost the locking key. Went to ereplacementparts, and bought the suggested part, which doesn't fit. What they sent is a key the fits into a single large slot it the middle of a switch. My switch has two small slots, on upper and lower part of the switch. I am presently getting by with two pieces of wood cut down from a popcicle stick jammed into the slots. Are the type locking key I need universal, and if so, where can I buy one?