Caslon No. 471 was ATF’s first version of Caslon, based on MS&J’s Original Old Style (later Old Style No. 71). It was followed by Caslon No. 540 (1902) with shortened descenders for standard alignment. Eventually, alternates made the two variations essentially equivalent. 1920–23, Thomas M. Cleland designed swash characters for Caslon 471 italic. [McGrew]
Caslon 3 (ATF, 1905) is a slightly bolder face. [Adobe] Various digitizations. Adobe’s and Linotype’s have small caps for the Regular. URW’s has the Italic only, but comes with swash alternates. ParaType’s (2002) is based on Bitstream’s and adds Cyrillics, designed by Isay Slutsker and Manvel Shmavonyan.