Is the long-handle ratchet highlighted in this pic the ratchet in question? I googled "Proto 5454a" and this is what I found.
If so, there's a little confusion with some of the comments. It seems some people in this thread are talking about the rebuild kits for the pear head ratchets, which come with springs, pawls and other little parts you assemble in the ratchet.
A rebuild kit for the ratchet pictured below will just be the entire mechanism in one piece and a new retainer clip, I believe. But that's assuming you can get one. I don't know if they do or don't offer kits for these anymore.
If you had to warranty one of these, I think they'd send you their Italian single-pawl ratchet that uses a mechanism based on the Facom design. I'm not sure they make the 5454A style anymore.