I would try McMaster-Carr. They have several different varieties of rubber matting. For example, part number 6897T522 is ribbed matting, 48"x48" that might work. Kube, I also needed the rear cargo mat for my '46 Wagon. I searched everywhere at Hershey. I was about to give up and stopped to look at some Ford parts from a company named Brownlees. I asked the gentleman if he had any floor mats for my car and before he answered me, a voice came from his wife in the camper. Well, I don't know how she heard me, but she answered, "I think we have one back at the shop". To make a long story short they had a NOS mat still in the original box and of course I purchased it.