Oh Mark, now you have me thinking back to the days of my father making potted hough, in steel wash boilers. My old man was a butcher/ hamcurer, and was involved heavily with the Ministry of Foods in WW2.
Anything and everything went into that cauldron of water and I mean everything! It went to show there was absolutely no waste then.
I was a very lucky wee laddie eating the finest butcher meat. As for the potted hough, just the smell of it turns my stomach !
Iain