So after a few diversions I have had some time to look at headsets and review the above information. The Shimano 600 is very appealing but I could only find 37.5 mm or JIS versions. After looking at photos of similar period bikes the Tange seemed quite appropriate for my frame. So I ordered a 33.5 mm Tange headset. Looking at Sheldon Brown's information I'm thinking my frame is a '76 or '77. So if it came with a Capagnolo headset then I am wondering 24 or 26 tpi. I guess I will find out when the headset comes and I try to fit it to the frame. I have found time to buy 2 other classic Raleighs - a Grand Prix and a Super Course. Both are complete and intact "survivor" bikes with little apparent use. Hopefully the Fedex trip goes OK for both. These will just need disassembly/cleaning/service and maybe a component tweak or two. I think I now have my winter free time accounted for.