Hi.. New here and have actually got a ford based kitcar which is running a cossie rear axle.. I am led to believe it is from a 2wd and maybe RS500 but am unsure.. It has a 7.5" lsd diff and 108" cv joints but the problem I have is that I managed to bend an arm with a closer than comfort encounter with an armco barrier on a track day I have managed to buy a replacement arm from North yorks cossie breakers but it is the wrong one.. Mine has a 30mm thick mounting casting were the hub bolts too and the one which was sent has a 20mm one.. Does anyone know what arm I have please?

Thanks