Alrighty - question for the auto body experts out there...

Dealing with a couple self inflicted wounds (sorry yada!), it seemed to make sense to also deal with the little rust bubble along the right rear wheel well. Peeling back the layers, it is now clear that the whole right side of me car has been "dealt with" at some point in the past.

On to the question: the filler used at some point in the past to pretty much re-sculpt the wheel arch on my car is yellow-ish in color. Smells absolutely NOT bondo-like when sanded. Seems to be pretty dang soft, pulling and shredding vs. nice clean sanding.

Any clue what the H E double hockey sticks I'm dealing with?

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1961 220b: first project car - sold.
2000 CLK 430: first modern Benz - sold.
2001 CLK 55: OMG the torque!!! - sold
1972 280SE 4.5: Baby Gustav
1991 300TE 4Matic: Gretel the Snow Bunny - sold
1978 300SD: Katz the Free Man - given away
1980 Redhead: Darling Wife