I have a Kenmore 790.75443411 and they don't have a part number for replacement insulation so it seems I must find some on my own. All I can find that states the dimensions is ceramic fiber that from most of what little I can find isn't safe unless completely sealed due to the fibers getting into the air being on the asbestos level of bad for you. Looking to find a safer type that lists dimensions. I need to go measure it myself but I would estimate the piece needed is about 2"x30"x60" max. The piece I need is the one that wraps around the top over. Someone took the cap off the center burner wile in storage giving mice a way in.
bio-soluble fiber insulation seems to be the set of keywords most likely to get you non-brand-specific results for safe high temperature blanket insulation. The "bio-soluble" part means it dissolves if it gets into you.
Pottery suppliers and other sources of high-temperature materials will have it.
Rockwool (aka mineral wool or stone wool) (not fiberglass) should cover the temperature range needed for a domestic oven, and is not classifiable as increasing cancer risk per The International Agency for Research on Cancer (according to the linked USA EPA document.)