Head model
FWIW my 1983 E28+ had a Wilcox-Crittendon Headmate in it. I was going to rebuild the pump but rather than doing that I replaced the entire lower portion of the unit with a Raritan PHC LBA. I kept only the bowl and seat from the Headmate. It actually seems like doing that was less work (and less stink) than rebuilding the pump would have been. The cost was about $220 plus new hoses. It's all like new now.