Steve, I would have sworn that 904 white always had black interiors as an option, with blue interiors also available on the 1970 and 1971 and red available on the 1972 and 1973 model years. Here is a page from TS71-47, which introduced the 1972 model year. Notice that it only lists one color interior for each exterior color, but it has asterisks for the new colors, so maybe they are just listing the new color combinations for those new colors?
The zhome site lists the following references for the information listed:
Documentation Of Exterior and Interior Colors
Note 1: Factory Service Bulletin, May 1970 Vol. 125 - "Introduction of Datsun 240Z Sports Model S30 Series".
Note 2: Factory Service Bulletin, February 1971, Vol. 137 -"Introduction Of Datsun 240Z Sports Model S30 Series (1971 Late Models)
Note 3: Factory Service Bulletin, Volume 171 -"Introduction Of Datsun 240Z Model S30 Series (1973 Models)
Volume 171 states the following: Please note: The Foreword states that " This Service Bulletin has incorporated only the descriptions and specifications for the modification parts and newly designed mechanism and others, but has not introduced the items continued from the present model vehicle."
There is no source listed for the 1972 model year information and the "Note 3" regarding the 1973 information says it "has not introduced the items continued from the present model vehicle." I wonder if that is the same for the 1972 model introduction?
-Mike