Under each wing on the AC is fitted what is commonly referred to as a "stone-guard". In fact it is AC's patented device for preventing muddy water from rebounding off the underside of the wing and spraying onto the external paintwork. But they do also double as stone-guards to protect the alloy wings from stones thrown up by the wheels. They are made from aluminium wire mesh, with a beading of thicker aluminium wire. These guards tended to be lost from most ACs, because the aluminium corrodes where it comes into contact with steel penny washers and mounting brackets. Therefore, improvements to their mountings would be recommended, possibly insulating them from steel parts with sheet rubber?
Rear Stone and Splash Guard
The rear ones are screwed to the body wheel arch using some of the same no.12 x 1 1/4" woodscrews that secure the alloy wings. Therefore, the mesh is in direct contact with the underside of the wings up to a short distance behind the wheel, where it bends downwards to a mounting bracket. This is a steel bracket (L-shaped but twisted), which bolts to the side of the chassis a few inches behind the wing-stay brackets.
The scale drawings below provide more details of this mesh:
Below is a photo of a right-hand rear stone and splash guard. They are not actually handed, except for the positions of the fixing screw holes.
Front Stone and Splash Guard
The front mesh is much wider than the rear one, and tapers from front to rear. It arches over the wheel (concentric with the wheel) and then extends almost horizontally back to the plywood wing support panel. It's front end is bolted to the wing with a coach bolt (5/16BSW x 1") and square nut (the same as used to bolt the sides of the wings to the wing-stays). Above the wheel, it is supported by a rather spindly L-bracket, its inner end being angled to mate up with the inner wing. The mesh is bolted to the wing-stay behind the wheel. The rear mounting bracket was missing from my car, but the bolt holes suggest that there was a very small L-bracket there bolted to the plywood wing support panel (the mesh fixed to this bracket with a single bolt).
The beading is a single piece of thick (4.06mm / 0.160" / 8swg) aluminium wire, that is bent tightly around each corner of the guard. The two ends meet at one of the rear corners, where one end is wrapped tightly around the other end.
More details are shown in the drawing below. The widths given are between the centre lines of the beading wire. Overall width of mesh, before folding over the beading, is approximately 25mm (1") wider than the figures shown on the drawing.
The photos below may help to clarify the above drawings.
Here is a close up of the design of mesh: