In general, if you can true and tension a wheel, swapping rims is the easiest next step toward building your own from scratch.
Originally Posted by
maartendc
Could I reuse the spokes if the ERD of the old rim is 598mm and the new one is 602mm? Can I account for that 4mm variation you think?
That's 2 mm difference in spoke length, about the outer limit for my comfort. Can you find a rim with and ERD closer to the old one?
Alternatively, you might want to build an entirely new rim for racing (I presume) and keep the old one for training.