[rrobson]

If you're flexibles aren't past it then don't bother changing them is the simple answer. They probably were 11mm many moons ago but if they're as old as the car some of the surface will have flaked off therefore reducing the size. You may be able to get a 10mm to squeeze on if you clean the crusty stuff first, a little heat will help too otherwise prepare to have to change the hard line if you fail. If you've got a decent flarer you may be able to cut a small section off and flare what's there but bare in mind steel isn't the easiest material to flare when you haven't got the proper gear which is made even harder on the car.

With the braided lines you need to be really careful how you route them too, plenty of people have suffered with them rubbing through!!!