Just picked it up for $10. From what I can find, its a rebranded Tamron Adaptamatic 300/5.6. Initial searching shows it to be a very competent lens. About 260mm long (with hood), T-mount, and has a 12 bladed aperture!
Need to take it apart and clean it, but otherwise good shape.
Nice find. The pictures in the link are encouraging. Maybe an early version of the Tamron Adaptamatic as the later one had a rubber focus ring: http://www.adaptall-2.org/lenses/670Au.html
Yup, first link for sure. I can tell by length and lens amounts. I can unscrew the front element and look into the guts.
Decent looking samples for such a simple optical formula. I was surpised by all the samples Ive found online. 100% crops look quite good. I am concerned how well it will resolve on my 60D. Worst case, I stick it on my backup 10mp XS.
Ill get some shots up in a couple days once I can give her a good cleaning. Thankfully I have a T-mount adapter already.