My model 10-6 has two holes drilled into the top strap. I know that it started life as a Virginia Department of Corrections gun.

The holes are over the barrel cylinder gap, and over the gap at the rear of the cylinder and the recoil shield. I've looked at them carefully, and there are no threads like it would be scoped (and for the life of me, I can't figure why they'd scope it). The hole over the barrel/cylinder gap isn't centered over it. Most of the hole is over the cylinder, with about a quarter of the hole over the actual gap, making me think that it wasn't meant to be a compensator hole (to tame the awesome recoil of the 38 special).

I've never seen anything like it, and when I lived in VA, I called the Dept of Corrections, but nobody knew, as I assume just about everyone around when they got the gun had retired.

Anyone have any ideas?

Sounds like some home gunsmithing gone bad. I would worry about the integrity of the top strap when firing the gun so it would not blow apart when firing. Too bad someone ruined a perfectly good gun.