Being interested in GDO's means that I'm interested in Acorns. Something I just found out a week or so ago is that the 955 was re-packaged as a B7G valve during WWII and designated 9002, with CV and VT derivative numbers too.
http://www.r-type.org/exhib/aaa0254.htm. I've never encountered any reference to them previously, but a few of them show up on ebay at no great cost.
B