Help with drawing a part

[PixMan]

I measured a few features on my 1982 vintage Alliant V42, and here's what I found:

Center distance between the two mounting holes, 43mm/1.700", 10.5mm counterbores, but the screws were actually 1/4-20UNC.
The slot measured 6mm wide. The "slider" measured .6265", so either and oversized 5/8" or an undersized 16mm. I didn't have time to disassemble it (and am disinclined to do so because I may need to use the machine soon.)