buying an orphaned brand TT?

I agree with what DutchmanSport says, especially about checking the condition of the used trailer carefully. THAT is the most important part of it, because honestly, many of the different brands are essentially the "same" anyway....just a different name on the outside. They all use things like furnaces, AC units, fridges, etc from the same suppliers. Everything in it, on it and under it can be fixed, even if the parent company is now gone.
Try to use the fact the company is out of business to drive a better purchase price for yourself, the seller may just want to get rid of it.