It did work. A tip of the hat to @
noglider for the suggestion. I eliminated 18" of cable housing and the Raleigh lever now has plenty enough travel to handle the Tektro dual pivot. Far more firm, much better feel. There is a BUT here though. This would not have worked if I didn't have this big 1" cable stop in my parts bin. I bought a brand new clip and used that with an old steel grommet. It wouldn't hold. The old Sturmey Archer clips are a bit more husky, but not as strong as the one I ended up using. Don't know who made it, not Sturmey Archer, but this wouldn't have worked without it. Maybe somebody makes bolt on cable stops for 1" tubes somewhere. I couldn't find one.
So this is a very useful mod and , I think, necessary if you're going to use dual pivot calipers, but you will need something stronger than a SA fulcrum clip. If I had known this, I would have brazed on stops while I had the frame stripped. edit: forgot to mention. The old SA clip does hold at the rear of the top tube. I think there may be more tension at the front. It was also handy that the Tektro connects the rear cable on the left side of the bike. Nice clean routing with the shifter on the right.
stops02.jpg