I recall several different configurations of CSMC in-the-white 20-ga. A1-Specials offered during their closeout. If the secondary market is any indication it seems that more 20s become available than 12s. Jay Shachter sold a Chris DeCamillis engraved 3-bbl. set that we discussed here:
http://parkerguns.org/forums/showthread.php?t=7582
and Puglisi's sold two others recently. Forum member Rex Northen posted pics of his 3-bbl. set that Ken Hurst engraved here:
http://parkerguns.org/forums/showthr...?t=6222&page=7