David,
Why don't you put those NP coaches on the for sale forum? You may be able to recover most,if not all, of your investment.
I see that David has done just what you have suggested. I think he has 1 of the NP 10-6 SLEEPERS, 1 OF THE 4-4-2 SLEEPERS, 1 OF THE Light Weight Aluminum Coaches.
He has a great price on them and I noticed on Duh Bay that Beth is sellinh last of these NP Cars.