Thanks Jerry, that makes how to install the Best and finish it clear. After all I've read, I don't think I'd be trying the job if the current leak didn't seem so big - hopefully I can't make it worse even with beginners skill level.
What my inexperience of these seals doesn't tell me is how rammed into the groove the seal should be along its length (as opposed to poking out at the ends) On my test piece I've got about 1/8" of the rope poking out proud along the length of half circle of the groove. When you use your piston to roll / press the seal along its length how close to flush do you get along the length of the seal?
Thanks for your patience!
Keith