Generally speaking, when shows are due to close, or see it on the horizon, they don't stock a lot of excess merchandise because it's money wasted on inventory they can't sell at a profit. What is left over is generally sold at the next BCEFA flea market.
You might get lucky if you're able to get to NYC and check the shops like in Shubert Alley that carry show merch.
However, if you can determine the merch provider, sometimes they carry things that the show's website no longer has.
Creative Goods NYC is one, though they don't have either of the shows you're looking for.
If anyone here has merch from those shows, check the tags and such, it might list the merch company.