My knowledge of early plastic sailing ship kits produced by toy companies is extremely murky. I know ITC did a
Sea Witch on about 1/128 scale, which later reappeared in an Aurora box and most recently in a Lindberg one. (At least I assume they're all versions of the same kit. I've only actually seen the contents of the Aurora version - and that was a long time ago.)
The Aurora
Sea Witch that I bought (back in 1970 or thereabouts) had hideous injection-molded sails cast integrally with the yards. It also had a sprue of miniature people who looked like crude ripoffs of Revell ones. I don't know whether the original ITC version had sails or not.
The photo of the Marx kit on ebay is too vague to say much about, but it looks kind of like what I remember about that ITC/Aurora
Sea Witch - with the very notable exception of the sails. The Marx ones pretty clearly are vac-formed.
I don't know what sort of relationship may have existed between ITC and Marx; I suppose it's possible that it's the same kit. But I'm inclined to doubt it.
Looks to me like a real historical curiosity - but probably not much of a scale model. There's no way I'd pay a thousand bucks for this thing. But (contrary to what my wife might tell you) I'm not a collector.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.