Spoke to Roy Pink cycles today about getting the wheel built - mainly because an internet search kicked up their name as a place that is pretty decent at working with older bikes. Roy said that you need to get a 28 spoke SA hubbed wheel exactly right or else spokes will get trashed very quickly, that it was "a complete sod of a job compared to building most wheels" but if built properly by someone who knows what they are doing, they should last pretty well. Erm here's hoping...