Ok, so I decided today to tackle the weepy brake pipe that I have on the drivers side and the drip appears to be coming from the second union. I figured that this would be an ok job to tackle, but no! It is seized solid, and will not undo. Are there any recommended techniques to employ to remove this section of pipe? I tried going to the next union along, just before it darts over the fuel tank, thinking that I could replace it from there, but that one is just as stuck. Any advice would be welcome, as I can't really continue with the rear calliper overhaul until this is sorted.
Cheers guys.

To be honest in situations like these we replace all and any brake pipes including the male and female fittings.

Thanks for that Joe, I guessed that may be the case. I had another go at it, and noticed that it was indeed the pipe that was shot, so I cut it off and undid it with a socket. A kind chap from the unit next to mine is making a replacement for me

That's very kind of him

That is exactly what I thought!

Just a note - almost all the brake unions on the coupe are the same male/female sizes, however the ones on rear brake compensator has 2 normal size and 2 larger ones.