Interesting - looks to be more or less complete, even if there are quite a few bits of other kits in there!
How much is this kit generally worth, in "unstarted" condition?
I recently bought a similar "scrap" Sea Witch model (arrived in the post today) however it's the Aurora kit rather than the Marx one, and cost me about £6 including postage, not $75! Similarly, it's a mostly-built and painted model which is distinctly battered, broken and faded, but appears to be complete, and the box included various other bits such as a few Revell 1/96 crew figures and some parts of other kit boxes.
I hopefully plan to start work on restoring this model fairly soon. Other than the injection-moulded sails, it looks like a fairly good kit. Like the Marx/Lindberg kit, it's about 2' long, around 1/96 or 1/100 scale.