brake calipers cylinder pads

[truckanddig]

At present I am restoring a Liner site dumper which I believe to be from late 60’s early 70’s,
It’s either a Liner Marathon or a Liner Roughrider, 3 ton 4 wheel drive with disc brakes all round.
These machines were built by Liner Concrete Machinery in Gateshead, Newcastle.
The discs are approx 330mm diameter and 10mm thick. I need to source 4 callipers, brake pads and a cylinder for this.
I identified the callipers and cylinder and they are as follows:-

The brake cylinder is a
Girling 875 7326.039

The callipers are
Dunlop 28K2 GC C2 1\8 patent no. 688382
10mm holes at 80mm centre to centre.