This is the pan and not much of a question mark any longer. Even the two oil spots can be explained via the two holes containing a non-hardening/non-curing fixative underneath. Might be some kind of dual-purpose adhesive/heat-transfer fixative on the underside. I can't find any other means of holding the pan in place and while I gave it a reasonable tug while twisting I couldn't free it. Bear in mind I didn't want to try too hard as I have none of that material in-house to replace if the pan came free. My feeling is that oily substance migrates under the heat inside. Quizzically there's also a female RJ45 ethernet jack between the two lower left capacitors you can just see in pic. Probably a diagnostic port but has me wondering hmmmm.
Statements in my posts are opinion only, not to be construed as fact. Any projects I engage in are at my own risk! Their outcome cannot be assured and may result in success, small/no change or catastrophic failure. I encourage no one rely on anything I say or do as gospel and to realize your mileage may vary!