Fox armoured car questions

[Bruce Parker (RIP)]

I'm looking for any information, similar things in other vehicles or best guesses on the following items in a Canadian Fox armoured car:

1. The brass catching tray for the main guns (Browning 30 cal. and a 50 cal. machine guns) has folding sheet metal 'trays' that appear to hing on a central channel anchored fore and aft. The 'trays' fold upwards and downwards to allow the driver to get into his seat. How do to trays lock in the horizontal position to hold the weight of the spent brass?

2. The guns are fired by remote cables (similar to bicycle brake cables) attached to pistol grips under the gun mount. These pistol gips look similar to ones used on other British AFV's. Do the triggers push straight in, or do they pivot around a pin at the top?

A sketch to illustrate these question is attached below.