Right everyone. Had a new J/B and fitted it and all is now well. Sorry I don't have one of these so called 'smart phones' so was unable to take any pictures. When this issue raised 'it's ugly head' I did consider crimp and heat shrink tubing as an alternative, but has I'd already contacted the supplier thought I'd wait until I'd tried the replacement.
I have an old friend of mine who works for the council and is a qualified electrician, but is currently off work at the minute following a knee operation, and he said he will be more than happy to call round when he can to check this out for me.
I will say at this point that I tried several other electricians before contacting my friend but none would entertain calling round and checking this out for me.
Thank you all for you kind help and advice