I recut my own dovetails on X and Y. At the same time I did some other machining to the mill to get it ready for CNC. Overall, it took about 8 hours for everything.
If I was just going to recut dovetails, I could probably do it in four hours.
Plan on making new gib strips with the correct angle and thickness.
It's definitely worth it. My only regret is that I didn't find a better mill to do the job on. The Bridgeport I used had some slop in Y, and that led to some variation in the new dovetails.