What do you want the tyres for? I have some old Specalized tricross tyres which I think from memory are 28's). They are old and have been used, but still have quite a lot of tread on them. However they have some cracking to the sidewall, not bad but still none the less they do have some.
I could send you some photos if you wanted??
Just checked them, they only have a little cracking and its on the tread not the wall. Bits of the wall are a little furry, from cleaning with a brush.