Some time ago (yes, this is another instalment in the loose ends saga) I wrote about wanting to catalogue all the different plate and perforation combinations of the 1923 Silver Jubilee set of the Netherlands (see here), to see whether it could be established when the various plates were made and used. But when I reread the information on this set in the Handboek Postwaarden Nederland, I found that all the information was already there! Lucky me! It transpired that almost all plates were made before production started. The only exceptions are plates 14 to 17 for the 2c, which were made in mid 1924, rather than autumn 1923.
Saves me a lot of work!