When it comes to loans and collateral I kind of doubt that basics change much over the decades. Back in the 70's we bought a new trailerable sailboat, and I asked our credit union about a loan. They said they did not make loans on boats, mainly because it was a product they were not used to having as collateral. OTOH, they would quickly loan us money on our almost new car that we recently paid off. Cars, they understood.
Sailboats are a niche market then and now, and perhaps more so, now.
Even when they are OK with lending on some boats and even sailboats, they are leary of anything that is too "used" and not having a well known secondary market. For instance, there are used car lots all over town with cars from 20 or 30+ years ago and there is an active market for them.
I would guess that the market for any older boat is kind of similar to the market for classic light aircraft. All cash.
My guess is that Deborah got that loan based on "character" and on the lender's books that was a bit more important than "collateral".
As for me, our CU would give me a signature loan, no problem, but well short of the purchase price of that boat. Deborah's "character" value is obviously quite high!
My .02 worth (of 'character')