I recently received a request from Katy for cooking tips when using a Tappan oven. This is a topic that I don't think we have touched on previously. The Tappan Deluxe models (and probably other models too) have what is described in Tappan Materials as a "heavily insulated" oven.
They actually talk a little bit about it in some of the Owners' Manuals. I have included one of the pages below.
The Manuals actually include pages of cooking and baking times (watch for manuals on Ebay - they come up frequently and sell for ballpark $10-15.)