If you Dura Ace wheels with worn out rims
there is hope! until now there was no hope as replacement Shimano rims are hideously expensive. However the Kinlin XR31T is available in 16H and 20H drillings. This is a lower spoke count than I would normally suggest and I would not guarantee the build against spoke failure for the life of the rim but you can at least reuse your hubs.
Given straight pull hubs are more than awkward to work out spoke length for I would need the wheels. i can measure ERD and the hub and find the fractional crossing number that gives the spoke lengths Shimano have used. Using the fractional crossing i can then work out the correct spoke lengths for the new rim. Otherwise if I have to work it out from scratch I will have to charge a extra fee for each new version of DA wheels that I see. It takes reall time to work it out the trial and error way.