I just looked at that Zenith porthole set on ebay. Very nice 3-way (early) home entertainment center from about 1949 (I remember seeing an old Zenith advertisement for this model not long ago--that's how I know the year it was made).
The cabinet looks good to me. I couldn't see any gouges or other so-called "flaws" the seller mentions, even when I supersized the pictures. I think whomever gets this will be very happy with it, if only for the beautifully crafted cabinet. They don't make them like that anymore.
I hope as well that the person who finally wins that auction knows something about repairing TVs, as most of today's TV repair shops won't touch a set of that vintage with a 10-foot HV probe.
The problem the seller mentions, "faint picture on . . . screen", could be caused by something as simple as a misadjusted AGC control, a weak video-amplifier or output tube, a weak or dead tube in the IF strip or, at worst, a weak or nearly dead CRT.
Repairing old sets is not easy in many cases, as I know all too well after having repaired (or at least tried to) many old radios, TV sets, phonographs, etc. picked up from my neighbors' trash 30-odd years ago; again, I wish the eventual winner of the auction the best of luck. Even if they cannot get the television to work, this set ought to make a good radio-phono combo if the TV's audio section works (almost all 3-way sets used the TV audio output stage for the radio and phono as well, and they sounded wonderful with those push-pull output stages, huge woofers and tweeters--they sounded and were built much better than some modern stereo outfits.)
If worse comes to worst and the entire set must be junked, the cabinet can be gutted and used to house a modern TV and stereo system (as many folks on this forum have done). In any case, I think a set of this vintage would be an excellent investment for the right person.