Inglis History
From what I understand of Inglis model numbers, they changed their method several times throughout the years. For 1964, 1965 & 1966 decoding is as follows:
The washers and dryers have a letter followed by 3 numeric digits in the model number.
The letter indicates the model year (not necessarily the year of manufacture): A=1964, D=1965, H=1966.
The first digit indicates the type of appliance (4=non suds washer, 5=suds washer, 6=propane dryer, 7=natural gas dryer, 8=electric dryer)
The second digit indicates the model line. This usually matches the name of the model but not always (2=Liberator, 4=Superb, 5=Normandie, 6=Sterling, 7=Citation, 8=Royal)
The third digit I believe is just the revision
My washer is a H470 = 1966 model year, non-suds washer, 7/Citation model line, no revision
Paul's washer is a H560 = 1966 model year, suds washer, 6/Sterling model line, no revision
Phil's washer is a D441 = 1965 model year, non-suds washer, 4/Superb model line, 1st revision from the original