Hi,
Thanks for all the help. I've been quoted £60 from another company for new decals which includes the time for designing them so have decided not to proceed. I've therefore completed as far as I'm going to go with it for now. As you say it just was not worth the time and money at this juncture for the frame to be sprayed and new decals. However as you can see from the picture I've de-rusted the bare metal including bolts, done what I could with the rust on the frame (it's patina!), new bare tape, new chain, new white wall tyres, new brake cables with black sheaths, freed the seatpost, trued the wheels, cleaned the hoods and toe clips.
It all works great and have done a short road test on it, which felt good apart from the terror of being clipped in while trying to use the frame gear changers! Not quite the winter project I was expecting.