I contacted the seller and this was the response.
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Hello,
well, thanks for your interest on my printer plates.
I got the whole lot some 2 years ago from an auction. I am a collector myself, but as I am not collecting banknotes from the countries I have listed printer plates of, I decided to list them for sale.
I´m afraid, on wining the auction I didn´t get any more information about where these plates came from, but I spend many hours over the last weeks scanning them, doing research in all the Krause World papaer money catalogs and describing the plates as accurately as possible.
I believe the collection of the plates was formed back in the seventies. If you look through all my plate listings (at least the ones for banknotes), most of them correspond to banknotes printed around the mid seventies to eighties era.
Each plate has exactly the same markings, writing and other feastures of regular banknotes, including accurate signatures. They are about 2 mm thick, the back is somewhat darker orange and bears remains of glue. POssibly the person who created the collection stuck them in an album or on a frame and enjoyed them that way.
If you look at my table you will see that the dimensions of these plates in mm are much smaller than the ones of your avergafe circulating banknotes. Maybe they printed the specimen notes first in smaller size and then extrapolated via larger plates to the actual size.
To send you bigger pictures I will need to rescan the plates. this will take a bit. As I cannot attach any fotos on your ebay email, please send me your normal email. when I get the opportunity I will send you larger versions of the pictures. Unfortunately they have seen some wear and tear. THe Zinc medal has on some partly oxidised forming zinc dust - all the white spots on the plates. So I may not get much clearer pictures than the ones already on Ebay, but I´ll try.
Please send me your email address.
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After doing some more research I am quite sure that these plates are replicas (maybe modern). I was looking at another plate from the same seller. It is listed as
Ceylon 100 Rupees SPECIMEN obverse. P#66 5.6.1963 S. Bandaranaike at right. ZINC Engraving / printer plate
57 x 29 mm
From The Banknote Book and from the actual note that I have the plate should be a lot larger. The Printer: BRADBURY, WILKINSON & CO LD NEW MALDEN, SURREY, ENGLAND. 163 x 86 mm.
Also none of my catalogs list a specimen for this note P66.
