Yeah the ones in the hex, believe they are 4mm x 24mm. We have all lost at least one, or snapped one.
As for the E clips, they are used for holding the spur on and also the hinge pins, again we've all lost one of those. For the hinge pins I now use circlips instead of E clips, I can't remember the sizes right now but you'll find them on DDM or RCModelz, or buy a selection box of them with various sizes.
Found what they are.
E-7HD clips are used on some front hubs, also used to hold the spur on.
E-4HD clips are used for the hinge pins.
Drive pins are 4mm x 24mm