This is a replacement drawer guide for a drawer in a rolltop desk from 1979. I checked a couple of other models on here and nothing quite matched up.  This design used the existing part as a model, but I made some changes for printability and strength.  The holes are designed for #6 pan head 1/2" coarse threaded screws.  There are two holes at the bottom for M3x12 BHCS screws for strength.

I went a little overboard and printed mine in ABS with a 95% fill.  This is absolutely overkill.  I printed like this because the originals lasted 46 years and I wanted the replacements to last longer.