CL Zenith...need help IDing it

[zenith2134]

I answered an ad for an 'antique 20 inch Zenith color tv, works great' the other day. Just got an email back saying the model is HE 735645 or something and that it's a cable-ready set with color sentry and space command. No pics, so I don't know if I should pursue this TV. All I have to go on at this point is that it was given to the seller in 1983 after their grandparents passed away.

It's listed for free, but I was wondering-- If its a cable-ready set, it must be a system 3, correct? Did Zenith use OSD at all in the early 80s sets? I have never come across one but who knows.... Thanks for any help here guys.