Can anyone identify these?

[Madmat]

So I came across these two bits in a box of random parts I have. I got them with an XR311 project I bought a long time ago. I'm definite that they aren't XR parts. I'm not really certain what they are from though! They each have a letter stamped on them, on has "B" and the other has "C" so I'm doing the obvious and assuming that they are left and right parts. I thought maybe they are from a Tamiya model in the same era as the Original XR311. I did have look at a few of the early cars Tamiya produced and these parts look almost like they belong on the sides of an F1 car rear wing, but from what I did look at, I couldn't see anything like these.

So I put it to you people. Does anyone recognise these. Excuse the poor picture, but you get the idea.

Cheers Matt