Looks like a generis Brand/Patent stamp. Depending on how it was stored, it may have ingrained particles in it and be useless for making clear stuff because of bubbles and blinding, but it should still be ok coated in colour. I picked up a heap of various boro (pyrex, duran, even some locally made australian stuff from when they were manufacturing boro tubing here, way back when) from a local university in the mid 90s. It had been in storage since 1974 and a lot of it had ingrained dust as well as scratches. Some of it went white (devit) immediately in the flame.
I suggest cleaning the tubes with dish soap and tap water first, then rinsing them with distilled or demineralised water before using them. The reason for the distilled/demineralised water is that it won't leave any calcium and other mineral deposits on the glass.
At the very least, they will be good for practicing on if you haven't had much experience with boro