I was recently given an almost complete and original Belthorne SSB IF module.
It was built as per the original Radcom articles from April/May 2000.
Included was a LO consisting of an AD9851 driven by a PIC16F84 but unfortunately no encoder, display, source code etc.

Hardware I got

Main board close up

Fortunately, the 'wayback machine' has some info archived

https://web.archive.org/web/20081017124424/www.g4gxo.cwc.net/belthorn_ssb_if_module.htm