Ez Block Of 4 Black Castle

is this EZ block of 4 worth any ?

One of the GB experts will be along shortly but the first they will want to know is which watermark do the stamps have. Makes a big difference.

What is a EZ block ?

Maybe EZ for EliZabeth? Just a guess.

Is that part of a pane division marker on the lower right margin of the lower right stamp?

This is one of the Elizabeth II Wilding "Castles." The cancellation seems to be for 1965. This is too early for the Bradbury printing without watermark (4 December 1967). On 14 november 1963, the Bradbury printing on whiter Crowns watermark (i.e. without the E2R cypher) was introduced. This catalogues used at ca. £ 5.50 (SG 1998, but has not moved much).

There is a slight probability that it is a De La Rue printing on Crowns watermark paper. Normally, you would expect someone to buy a block of four £ 1 stamps for registered mail from the counter. Making Bradbury the most likely printer.

The cancellation is a registered mail cancellation. Collectors are not very keen on those. Also, most stamps in the block have missing, shortish or bend perforations. That would lower the value considerably.