There’s a really interesting article about photographer John Duder going back and experimenting with filters he never got around to using in the 80s over on ePHOTOzine: Experimenting With Filters From the Eighties I Have Never Used – Come Check Out The Results
Also interesting that we’ve got many of the filters he used here on PhotographyAttic. check out our Cokin A-Series section and the Cokin P-Series