Okay, a couple of work in progress pictures.
First the Crusader (yes I am still working on it).
Thanks to Pinky I have a picture showing the stowage rail (and Osprey have a rear view picture in Campaign 220: Operation Crusader).
I do worry that Crusader MkIIIs do not have the stowage rail, but it is now a bit late.

I should have checked the position of the end of the long six pounder with the turret rotated to the rear, luckily it just fits but I will need to be careful with the stowage when I sculpt it.
From the Osprey picture, I am building a jerry can rack to go above the radiator grill (yes I used the grill that does not take the spare fuel tank). This is a work in progress shot.

Four cans from the German Stowage set with the rack made from 0.030" square section Slaters micro strip and straps made from 0.030" by 0.010" micro strip. The end pieces of the rack need to be added and a lot of trimming is required.
It is being built on a glass plate to make it easy to remove.