[R-390] Zenith Trans-Oceanic

[David Freeman]

Off topic, but there is so much general knowledge on this list...
Is there a definitive web-site to learn about the older large Zenith Trans-Oceanic radios? I'm interested in getting one, but can't figure out which. I want it to use, so performance is more important, (assuming there are any differences). Seems like there is a large disparity in $$ on e-bay. Are some that much more rare than others, or is it just e-bay lunacy taking over that makes some identical looking radios sell for $200 and others $30?

Dave, WW8S