I now possess a Sakar 28-200 f/4. It's a massive thing at 710g, solid and ambitious. I'll give it better inspection and evaluation in the next few days, but first to bed and hopefully far away from this headache. It's in good shape, I'll say that much for it!
I took the lens for a short stroll; it performed well, good contrast and decently sharp. It has a curious feature I don't recall from any recent zoom: the minimum distance to focus varies based on focal length! AT 28mm it stops at 2.5m, 70mm=2m, and so on to 1.8m / 6' from 100-200mm. Curious. It also has no 'macro' setting so getting close to your subject just won't happen; a quick test measured magnification (shoot a ruler, divide mm in long axis by 24 for aps-c) shows about 1:8. When this lens was made some big compromises were needed to have this sort of range, so they chose not to worry about close focus. My Vivitar 28-105 has a 1:5ish option at 105mm so its versatility shows there, plus being 200g lighter. Both did well in today's walkabout, but neither were able to get a sharp squirrel image on the fly like an AF lens. Some of that was due to flat lighting though; I should have been higher up the iso scale today.
So why do I own this 700-gram monster? Well, it was paired with a Kiron 28-105 on shopgoodwill website - one of the lenses was PK and one Canon, and the images were unclear on which was which. I put in a base bid, hoping the Kiron was PK, but later discerned which was which after close exam of images showed skylight filter on Kiron, UV on 28-200. By that time my cheap bid had won: less than $20 for the pair! At the very least I should break even when I resell (one or both!), at worst I donate them again. And I learn a little more about old lenses.