Manuals

If you "feel lucky" you could ask for these parts numbers at your local honda dealer... (actually the first two, non model specific should be easy to get)

Factory Shop Manuals	Year	Part Number
Common Service Manual	-	61CM001
1959-2000 Honda Motorcycle Identification Guide	-	2GMAS00-AH
CB450 Super Sport	1965-68	622835
CB/CL450	1968-75	6228301
CB500T	1975-76	6137501

Below is my "reference libray" - so far

Books	Pic
Parts Lists
CB450K0 - Parts Catalogue	X
CB450K1/K2 - Parts List	X
CB450K3-K5 - Parts List	X
CB500T - Parts List
Shop Manuals
CB450K0 - Shop Manual, Provisional (1965)	X
CB450K0 - Shop Manual, Super Sports (1966)	X
CB450/CL450 - Shop Manual (1968)	X
CB450/CL450 - Shop Manual (1972)
CB/CL350-450 - Shop Manual Supplement (1971)
Owners Manuals
CB450K5 - Owners Manual	X
Others
CLYMER - Honda 450 & 500 Twins, 1965-1977