Many thanks for all the replies
Here is the vessel the plate is on.
Macwester 26 archive details - Yachtsnet Ltd. online UK yacht brokers - yacht brokerage and boat sales
I am working on a westerley Griffon at the moment I will try and rember and take a picture of that plate as well..
I did think the bottom number could be the length of the vessel...
Last year i was working on a oldish crusier that was 45 foot long it also has a plate. set out in the same format....
Here again is the same vessel with another tpe of plate see image 4 or 5