I recently purchased a Jaguar XJ6 from an estate that came with some Jaguar spare parts. The owner had among other cars a 1962 Mark X
I have 4 calipers but no markings from Dunlop or Girling. They look like E-Type Series 1 but that may be the same as a 1962 Mark X.
Any help in identifying them?
Monza275

 

Mk1, early type. Jaguar part #6905. I found it in the Jaguar heritage parts site which is priceless as reference.

 

They are very early Dunlop wheel cylinders used for the calipers fitted on the Mark 1 saloon and also, I believe, the XK150 sports car. They used circular pads, and renewing pads was a real PITA because the caliper had to come off to replace them. It wasn't long before Girling improved the design and introduced the calipers that used the square brake pads. The wheel cylinders for the two types do look very similar. Both types used a pad withdrawal mechanism on the piston.