"Sadly some of the older Weavers get very poor in the clarity aspect, some say because the lenses are glued together and the glue degrades."
I think that may be an issue. However, I have a Marksman, a K6, and a K3 that still function well. I have seen some old Weavers with clarity issues though. I didn't know about the glue thing.
I have several of the straight tube 3 and 2.5 power weavers, favorites actually. some with the glue issue, mostly 4 powers. It looks like bubbles in the glue where it has separated.