I ended up buying continuous zips with separate sliders, so I now feel quite an expert at putting the zipper back on. I am just not sure how to do it on a jacket. I will have to do some more research on youtube to find out if it is possible.
I did this on DH's favourite round the garden or down the street jacket. I bought it from C&A so you can tell how old it was. Anyway the zip just wore away from the sides and would stick going up. Half the battle is taking out all the stitching out so a good ripper comes in very handy. At least I got an idea of how a zip placket works. It was a good job done, but he was examining like it was a really expensive jacket.
Gave me some practice for taking a lining out on a new casual jacket because it made him hot and replacing with a cotton one. That was a top notch job, I even did new welt pockets on either side.
Funnily enough I'm just doing a jacket that needs a 20 inch zip and in that colour the one I already have is 22 inch. I think it might be easier to just get another zip.
What niggles me is that I have a new curtain pole stood in the dining room that has been there coming up to 5 years and he's still not put it up.