For a wing mount your options are
1) use some long bolts and spacers to screw the wing to the mounting point for the saloon rear body mount.
2) get hold of the old style wire wing mount and mounting hardware, as you can
see here. Doesn't matter which car it's off, as long as it can mount to the shock mount.
3) buy another Procat or a Cougar1. Buying a worn out complete car will be cheaper and easier than trying to find someone selling the original wing mounts.