I received a Morebeer 2100 back in October and had issues priming on the first few batches with the purge valve on the inlet side. I changed the configuration to have it on the outlet and have had no priming issues since.
By skirt I meant an outer piece of 1 x 12 around the 2 x 6's, so the 2 x 6's are what sit around the freezer top and the 1 x 12's hang over the edge another 6 inches. I don't have anything around the bottom.