Hi, I'm reading about your split moulds with interest. Just about over the same period, I've been making moulds to make some motorbike parts, a rear hugger and some heel guards.
My first hugger mould had some mechanical lock, but I was able to get the part free, though damaged the mould so remade it. In the second mould, you can see that I moulded in some ejector screws. In the pic then sddrews are in the wrong side of the mould. You simply wind them in and the part pops out. The cool part was moulding the nuts into the mould.
I'm now on my fifth pull from the mould using wet lay up. It's quite a complex bit with loads of corners and curves, so getting a bubble free part is nearly impossible, so I'm just moving to vac bagging next.
With you mirrors, I'm interested in the split mould because I'll be making wing mirrors for my bike too, which I guess will have to be split, maybe even three ways.
Keep posting the photos. Really cool stuff, hey?