I've posted this on /p/ and photographyonthe.net and figured it was worth posting here.
I've had one of these laying around that I meant to fix for a while. These are the little-known but much-respected kit lenses, the EOS 28-70 f3.5-4.5 that came on the EOS 650. They're about 100-ish dollars on flea-bay and broken copies for MUCH less. Once in a blue moon they pop up on here in EOS 650 kits with Mk.I 50mm's and 70-210 f4's. You will want a broken copy with a front element assembly separation.
The front half of the lens, the focusing part, had separated in a drop apparently and hearing that the MTF charts were only bested by the 28-70 f2.8L I figured I'd keep it and fix it up.
So it sat for a while, a LONG while, and tonight I pulled it out to dust it off and maybe order the part to fix it, when I mounted it on my camera to see if the aperture still worked and everything I discovered that the damn thing makes for an excellent macro close-up lens.
If memory serves me correct, people have been doing this with 35-80 kit lenses. But I never heard of it with a 28-70 kit from a 1988 EOS 650.
Samples below @ 28 and 50mm. From what I've shot so far I am very impressed with the level of detail and the background blur. Stopping down adds a significant amount of DoF, especially f11 and above. Also shots of what the whole thing looks like bolted up to my EOS 5d