Hi Otto, I have got a cycle wing PA that was converted many years ago. I used the original wooden part that was the filler for the swept wings as a partial pattern. I made them from 12 mm marine grade ply and clad them with 1.2 mm aluminium. The original fixed brackets were used for the existing bonnet catches. From memory the front fixings are single bolts passing through the high point of the chassis above the axle and the rear fixing mounts on what I think was the original angle bracket that bolts to the firewall uprights.
If this is any help to you that's fine and please contact me if you require any more information.
Thank You for the valuable hints! After several attemps with the existing original wooden parts the way You did it I wasn't happy with this approach and so asked Steve Gilbert to do the side valances for me asYou can see on the attached pictures.
Ideally Otto, there should be. swage line along the leading edge for the bonnet side to rest in, similar to the J and F type if you are going down this route
Hi Otto, I have been through this with PA 0817 which has been converted to cycle wings. As Rich has said, mine has a swage on the top edge and you will note that it has some aluminium machined to take the buffer strip rather than a series of holes. (That aspect is not an original detail but it does work very well for the bottom edge of the bonnet.) Some photos attached with the detail.
... a long time is was not happy with sharp edge of my parts. One day i had seen the brass pipes from the centrtal lube system and use it. Silver solder was a good solution.