Glenn, there is a family member that was on the forum a couple of months ago. His grandfather was the designer/manufacturer or some such thing. Lots of them made, not many left. Do a search for winkler and you will be pleasantly surprised.
That is the remains of a bituminous stoker.. they were meant to be installed in hand feed stoves. You would remove the grates and ashpan. You inserted the stoker through the ashpan door and under where the grates were.. a high temp cement was poured around the firepot sealing the combustion chamber..
There was quite an industry for these add-on stokers in the 30's and 40's,, oil was becoming so popular that coal was feeling the pinch.. I have several trade newspapers labeld 'The Stoker News' all about this type of stoker unit.
Several makers I can remember off hand: Iron Fireman Winkler' Will-Burt [bought Iron Fireman] Delco Massey-Fergusun In total I counted 12 or more different makers.. I don't have time to dig out the trade papers right now.
Moving this to the Bituminous forum for better exposure