Nice job getting it all cleaned up!
It appears the boiler had some kind of firebox surround, judging from the holes along the side of each vertical framing member. Despite the markings, it sure does look like a well-made home-brew. Intriguing.
I note that the burners are recessed into the base. Is this a spirit-fueled setup, or perhaps piped for gas?
Thanks for posting the pic.
Paula