Hi jack - you got a PM
As for the brackets - i got hold of a set from a F60. I thougt they would fit, all holes were in the same position, but the bracket itselve had a slightly different size.
On my Chevrolet there are four holes, two upper and two lover in the vertical section of the chassis for mounting these bracket. But I have also seen on a C15 these brackets mounted with three bolt on a row.
Heres a (bad) picture of my frame with the four holes on the left side.
And heres the brackets on a C15:
