Got myself another Britool tool chest last week. On the side of the box it said Stanley, Britool, Facom. So there's 2 other reasonable companies that might start to go downhill.
I spent hours trying all sorts to get that one off. In the end i borrowed a 15mm flexable head ratchet spanner from a mate. It does go back on easier than it comes off.
Work had a tri-axle Ifor Williams taken about 3 weeks ago as well and around the same time a company down the road had a few vans stolen. The vans were found in South Wales on the way to Pembroke docks.
I've got the same master and slave as you, like Phil says its a early slave and a later master cylinder. On mine I already had the larger series 3 flexi clutch hose so I got another adaptor and screwed it into the slave then used 1/4" od pipe.
Dont know if this will happen on a 80" with wide springs but when I fitted S2,2a,3 springs on my 1955 86" I found the trackrod rubbed on one of the clamps on the front spring. The clamp on the original springs was further forward.