Extending shower circuit cable

[ringer]

Not really extending, but replacing knackered end of cable. Customer has ceiling pull-cord switch for shower not working. Switch is knackered and 6mm supply cables are corroded and their insulation is cracked on conductors that are showing within the switch. Load cable looks good. I am hoping this is just local to the switch! Need to go back tomorrow to fit new switch and am considering how to tackle this if there is not enough slack in the supply cable to pull through and cut back to good bit of cable for termination. If I have to cut back substantially and fit new portion of cable from within the loft, how can I make the joint?

a) 60A junction box (which I don't have)
b) crimp and sleeve (have crimps but no sleeving)
c) 50A terminal block in a choc box (which I do have)
d) any other suggestions?

Getting to a wholesaler is not impossible, but would be inconvenient. Will the term block in a choc box be acceptable?

 

[Deleted member 26818]

Three 100A SP Henly blocks, or one DP Henly block and one SP Henly block.

 

[SirKit Breaker]

Option C would suffice, but connector block has a tendancy to work loose and you will have the same problem again, and conn block also looks rough no matter what you dress it up in
I would do as spin has said, at least with a henly you have 2 screws and get it really tight.

Cheers..........Howard