Jewelltrail,
Wow, happy to read you think it might be a winner, though still a little mysterious.
It's a true M42 mount and lots of plastic, and the font for "Tamron" looks different, too. I would think it is later than earlier, but don't know, even after looking on the site that documents Tamron lenses. It's takes a 62 mm filter, so the slide up hood is a plus, don't have any filters that big yet.
What I really like is how true it renders colors, the dog and pool colors are spot on. Here's a mundane shot of the lawnmower, first one I tried with this lens.
But I'm posting it because the red is so true, and again, hand-held in awkward lawn chair with Kenko 1.5 TC, don't remember the aperture. This one is sharper, can see even specks of dirt when I cropped it in Aperture, so I am happy with this lens. Sorry about the quality, still figuring out how to upload larger files.
Thanks for your comments, and thank you, too, for your fine photos of New England, especially with the 17-50, they are spectacular. Makes the lens hard to resist, but in reality, the budget makes it very easy to resist! And the fact that I'm a real novice and need to practice, practice, practice with the fine lenses I have first, before another indulgence.
Sharon