Parts for A-S Re Nu Shower Valve, model R1400?

I have an American Standard parts list for this shower mixing valve (Re Nu, model R 1400), but haven't been able to find a source. Any suggestions? The house was built c. 1961; the shower valve is on an outside wall and the tile is in good shape, so I'd prefer to repair rather than replace. Thanks!

-Bob

Brownspartsmaster (BPIsite.com), may be YOUR best option because the site where I would get them only deals with plumbing contractors.