Right, I was supposed to be going to my time trial today but instead I'm writing this which gives you an indication of how well my Saturday went.
I had noticed that my master cylinder was copulated so ordered a new one, paid extra for it to arrive on Saturday, didn't get here till 215pm! Dashed about getting brake pipes, flaring kit, connectors etc
Stripped out old M/c pipes running between t piece and M/c, made up new pipes, fitted new M/c and got it all nipped up again.
Bearing in mind I'd never done any of this before I was doing ok. However I went to bleed the system and over tightened the rear bleed nipple f**kulating the threads... I was a bit annoyed with myself. My Old Boy, who was helping, came away with a cracker after I did it, "you only need to that up then a quarter turn". Information that would have been good 10mins ago..

Mate Phil came through as he nipped up with a replacement nipple, continued to bleed the system, turns out that new nipple won't seal caliper and was peeing brake fluid on drive. Phil also lent me a new set of calipers he had in the garage so may change rear caliper later to get MOT.
Question, would it be safe to enlarge/tap the bleed nipple hole and seal it with a bolt? Or will I need to stump up for a new caliper?
This is the edited highlights, suffice to say I gave my best but was thwarted at the last. Didn't make it to the meet/ time trial as I finally gave up at midnight on Sat.