Owens-Illinois SunPak hot water solar collectors??
 

anyone heard anything about these collectors. i did a google search on them and didn't come up with much information on them. it does look like they were introduced back in the early 70s during the oil crisis. and it looks like they are evacuated tube style collectors. anyone know if they are good or bad?

there is some forsale by me but they kinda have me concerned. seeing as they are old and glass repairs could be nearly impossible. at least with a flat plate style you could probably repair leaks if one was to arrive.