As I had the bits for doing the second caliper, I went back into the garage and messed it all up. For those that don't know, the top seal is held in place by a metal collar, and it is very easy to get this wrong when pressing it in. And of course I managed to do it when I had had no problems with the other 3 I'd already done. So having contributed vast amounts to the swearbox, I put some more seals on order, shut the garage door and left it for a week. New seals arrived, and I promptly did the same thing again. More swearing. I was then ultra careful with the final one and had no more issues. Calipers done! (Although they will need a further coat of paint...)
I have decided that as the temperatures have dropped and there is no heater in the garage, even with a "hot" mix it's not really worth doing any filler work, so I have turned my attention to some more mechanical things. I have got my hands on a KAD Quickshift (rescued from a friends garage for a decent price - he happened to have two! - but I couldn't get the lever's collar to engage on the extension. As I have a spare full selector anyway, I tried that one. No issues at all. Now what it needs is cleaning as it is not pretty. Parts washer is on standby...
Caliper finished! (Apart from more paint)

KAD Quickshift acquired (Really must pay for this...!)

It's a bit gungy in there...
