Whats the worst that can happen?
I would be well impressed at myself if I were to cause £125's worth of damage, most likely with the wheels?. I suppose a more valuable bike can be intimidating, but as said a concidered approach and access to the relevent reference material works wonders.
I am sure a 'wing it' approach produces mixed results or at least it did with me, before the internet(much less reading a book). This was probably not helped by not valueing these bikes as they deserved, if you could nip down the dump and get a replacement for next to nothing.
Sadly at least at the dumps I visit these days, this no longer seems to be an option. Where can you now get any old steel at scrap value?
www.madegood.org , looks good as was posted on here recently, although Sheldon and here covers just about everything I have wanted to find out. Now if 'The bearded wonder' was still running courses, I would pedal a good way to attend!
Lidl do a very useful and inexpensive moulded box 'repairs tool kit' that has stood up to use surprisingly well, if they regularly stock the thing so much the better. As it seems to surpass many other multi kits I have seen and at a much leaner price.