Graybeard/Neil,
Those are great pictures and very helpful. I have to say, the mod that was done on the shell I have is very neat and it took me some time to realize it was not original off of some bike, BSA or otherwise.
Jules,
If the shell mods I have are what you are looking for, I would readily consider a trade if your shell is an unmodifid version like Neil's. I could buy one for about 100 Euro (including shipping), but I wouldn't be asking near that much for mine, again, assuming you or someone else wanted it.
Richard L.