Tempwood Firebrick / Mortar Question

[tempwood_guy]

Hello! I have an old top-loading Tempwood stove, which was made in the Berkshires back in the 80's. I need to re-line the side of the fire box with fire brick, which is straightforward. But I need information on how the bottom of the stove was originally configured. I have a rectangular steel plate, but does any know if the plate was under a bed of mortar, or if it was surrounded by block? (This stove was stored upside down, and the bottom of fire box caved in.)

I don't have a model number, but I have attached a picture of the stove.

Thank you for any information.