Thanks for trying! I'm also of the theory it's steelcase but it also has no "Steelcase" logo beneath the keyhole in the center drawer, and no residue etc I can spot in that area.
Snagged one from local college surplus for $50. Having a hell of a time identifying the model. No labels in or out as far as I can tell. The key hole is labeled "1369", didn't come with key. 29.25H x 60.25W x 30.25 D. Cleaned and superlubed, need to figure out 3D printed inserts + bearings...