I need to model MBS coupon stack prices. It would not be difficult to create something from scratch, but I don't want to re-invent the wheel (and explain why I did) if a somewhat standard model already exists. By "somewhat standard", I mean models like those for the term structure (e.g. Nelson-Siegel / Nelson–Siegel–Svensson or some newer stuff by Diebold et al).
I would appreciate any pointers, no matter how obscure.