Originally Posted by alcjphil

What I would do is to try to find a clincher rim with the same ERD as your tubular rims and do a rim swap: Tape the 2 rims together, loosen the spoke nipples on your current rims a few turns, then one by one disconnect each spoke, transfer the nipple and spoke to the new rim until they are all done and then gradually tighten the spokes equally after the transfer is complete. I have done this dozens of times over the last 45 years and have rebuilt dozens of wheels this way