Hi Flow,
Images attached.
The first pic shows what was supplied straight from the box and shows a yellow plastic washer between the hinged swivel bolt (that locks the fence in place) and the cast bracket. This as what wouldn't hold square when tightening up the fence.
The second pic is how I've got it now, with 2 steel washers, which holds the fence square whilst tightening up the bolt.
Yep, you're right about the depth setting bolts, just a simple bolt with an extra nut. Set the nut at the desired depth, then tighten the nut up against the plate to lock in place. They can be seen attached to semi-circular bracket mounting the fence. For some reason, when I set the lower one to give 90degs and the upper one to 45degs, they went out of true when tightening the swivel bolt (mentioned above) so I took them out for now. It seemed the whole assembly was pivoting on the depth bolt and being pulled out of position when doing up the swivel bolt.
Also what you can't see in the pic, is what looks like a little crack in the casting where that lower depth stop bolt goes. I'd annotate the pic with an arrow or 2 but, don't know how to do that, sorry.