You are right, Metaxaloy was a type of synthetic rubber. It was vulnerable to betting punctured by pencils, nails, screwdrivers and other sharp tools left in pockets, although the two that failed in the 50s in my neighborhood died because the transmission seals allowed water to leak into the transmission. Like a lot of things Bendix, the quality suffered after Philco took them over. The washer was a wonderful idea. It was cheap to make, did not use a great deal of metal, only used a wringer washer transmission and was virtually vibrationless so it was a great machine for young families living in apartment houses. They were not so great to have when people got clothes dryers because they left laundry with a lot of water to evaporate. It is sort of ironic that this toploader left more water in the load than any other toploader while their washer-dryer combination left laundry with the least amount of water in the load at the end of the spin.
One Bendix service tech told me that the rubber-tub machines bankrupted Bendix, maybe because of the 5 year warranty on the tub, but I don't know if that is true or not.