Mike, as far as I know, all the major saw builders warranty their work, and as it is the dealers responsibility to send in the warranty cards, the rest of the saw is covered by that...the only problem I have ever run into, is once, a saw that I built needed some warranty work done, and he took it to another dealer, who upon seeing the cylinder work refused to do it. The warranty work had nothing to do with the work I had performed, but he had to bring it back to my shop to get it done...where it wasnt a problem.
You definitely did right in checking first though...you will love your 357 once it is done up!!