Just found this thread. There is a vast amount of info on super-regen rx and the associated fremodyne rx on
http://members.iinet.net.au/~cool386/index.html
Tempted to have a go - it's 60 years since I last made one, using a 954 acorn valve {PW, I think] It worked...but tuning was by adjusting a slug tuned ex-telly coil.
73
John G8JMB