I may help you out with the brakes, Neil, if you promise to swap the saddle (and maybe the seat post), too! ;-)
Did you ever look out for a Bassano Vuelta saddle?
One of the best saddles my bum ever met and (match the frame tubing), Reynolds 531 rails.
There must also be a couple of hundreds, if not thousands, with Gazelle name or logo on the back. Just a tip.