I went to swap the winter tyres from rear to front today and was met with a completly shredded outer boot

quick call and the local motor factors had a pair in stock (from 1993, judging by the amount of dust & date stamp on the large clip !!!). so no questions asked regarding cost etc (turned out they were ONLY £6! )
howver when I got drive shaft re-assembled and pulled the boot onto the outer end it was 'affy ticht' and studying the other one in the kitchen over a cuppa it seems to have extra ridges on the inside which , i guess, are meant to help with the sealing but as they are not at the extreme edge mean that the clip looks as if it wants to slip off

made the school boy error of putting the grease into the CV and some into bellows BEFORE assembly, I reckon it would have been less messy to assemble it dry and then apply the grease into the bellows!
just for info the HBOL says to expand the circlip and insert a 6mm screwdriver whilst you pull off the outer CV joint, you ACTUALLY need to use the circlip pliers to expand the clip to maximum and it will then wiggle free.