Dave,
good write up as ever...!
I've not played with Aldermogs brakes, but have stripped and worked on motorcycle brakes. A couple of comments from that experience.
1. The idea of pad retainers that are not positively fixed doesn't impress me one bit.
2. The springs should be changed whenever pads are changed: they are there for a reason - to keep the pad seated and stop it rising up - and they get weak with age. One reason the pads have a ridge on them is that the springs are not strong enough so they ride up under braking.
3. The pads are too large for the disk. There should never be wear as you example. If there is a ridge it should be on the disk, not the pad.
All this reinforces my belief that the stock front brakes are cheap and nasty. OK, I'm a bit obsessive about brakes, suspension and tyres, but that is the result of riding a bike from 1967...until 2013 without coming to grief.
All your post has done is convince me that Aldermog needs better brakes.
