Good heavens you work fast, whenever I try to take my bike apart there is always some corroded bolt that refuses to come undone and turns a ten minute job into half a day spent cursing. Having said that, all the bolts were greased when I put the bike together but then some of them haven't been touched for fifteen years.
I don't think the brakes have been dragging for long, I just noticed it when I wheeled the bike back to get on the other day. Looking at the caliper it has oxidised quite a bit more than usual this winter and I suspect the pivot at the top is not moving as it should. One day I will learn and will clean my bike occasionally and perhaps even put it under cover. Then again it's probably wishful thinking.
What you have said is very useful because it has reminded me that I will need to buy a new piston seal before I take it apart as well as some new brake fluid.
Someone mentioned brakes locking up in the wet. Can others please confirm this. The brakes on mine have so far been pretty rubbish so I find this revelation rather surprising. Does this mean that the only advantage of drilled disks is in wet weather?