Thanks for the comments here, lots to think about. I am in Bristol at the moment,I can walk to Argos cycles quite easily from our house so it made sense to take it there. Surprisingly there is another Walvale in there having some work done on it too.
As for the setup I think I will stick with the Top 63s and Universal levers especially if I can get the new rubbers (at a price
). I want to stick with as much of the original equipment as possible, partially for sentimental reasons and also because that is how the bike was when it was first built up and ridden. Surely ebaying the brakes would be regarded as selling the family silver!
Regarding the brake shoe there are a few options - any shoe with a threaded stud should work if the stud is long enough, that is what was used for a long time. I have seen more modern brake shoes in a similar style that could work too. Or as suggested tap a thread onto an unthreaded Mafac shoe.
What are people's thoughts on Simplex rear mechs from this period, this is one part that I need to get off ebay or suchlike. I have heard that they can be quite prone to snapping, not good if I actually want to ride this bike... I was thinking of going for a Record mech instead, plus they look better IMHO?