Case built tractors in series with models within that series i.e. the "V" series had 8 models VC, VI, VO, VA, VAC, VAH, VAI, VAIW, & VAO also sub models VAC12, VAC13, VAC14. Each tractor was built for a purpose although they all are somewhat suitable for general use.
The B series tractors were built in model years 1958 - 1959. The B series included 200B through 900B with models within each series i.e. 300B series are models 311B, 312B & 310B, The 400B series are models 411B & 410B, etc. The 11 in the model nr indicates the tractor is general purpose sometime referred to as AG or rowcrop with adjustable front and rear tread, usually used for farm work. The 10 indicates the tractor is a utility or industrial, considered fixed tread, usually used for loader/backhoe type work.
The earlier 1955-56-57 400 tractor is round nose, larger and higher hp than the later 400B models.
The 1st pic is a 410B utility and a 411B rowcrop. 411B front can be single or dual wheel (as pic) or it can be an adjustable wide front end as pic 2.
The 400B series tractors are basically 300B series tractor with COM. Many parts are interchangeable so for the most part they both use the same service, parts, and operators manuals. If there is a dedicated page(s) or parts for a specific model it will be so noted at the top of the page or in the parts lists.
For parts for 400B series go to the link, enter 400B in the model search box.