This is a great find, Jack. Well done!
As soon as I saw all that grime on it, I knew it would be very likely be mostly well protected underneath it all.
Interesting to me are the 2 immersion heaters. All other's with the belly heater have 2 cartridge heaters which leads me to believe the engineer who added the ratchet drive oil pump may very well have replaced them with threaded bosses and immersion. He certainly knew what he was doing around his steam engines.
Gil