Energy Harvesters Vintage Woodstove, Does it need firebricks?

[Nastilian]

I assume this will be an easy answer from an old timer that remembers when these things came out.
I recently installed this stove (model #1), it has the diverter plate up top, but missing the front screen, and the pad that fits in front of the fire box.

My main question is this.
Does this stove require any sort of insulation or fire bricks on the sides or the bottom?
I cant locate the service manual, and put some bricks in the bottom and a few on the sides as pictured, but it shrinks the burn box significantly.
I've read you use sand in the bottom of some of these old stoves, but wondering from someone with experience what was the spec when it was built?
Did it come with any insulation on the sides or bottom? Does it need it?
Or is this iron strong enough so that its not required.

Thanks in advance for any insights that can be provided.

 

[begreen]

I don't recall seeing any side panels on this stove. There should be some clean sand or enough ash to cover the ripples in the base plate.