Do they sell gas caps with locks as a spare part for a 99 Ford Escort Sport.?
If it is leaking around the glued joint then no you can not fix it with out replacing the joint. No glue or compound on the outside of the glued joint will hold the water pressure from leaking when the water is turned on. It needs to be replaced.
The knobs turn a center opening that pulls the strike away from the door frame. Stick a screwdriver into thje center of the locking deal, and turn it side to side forcefully. Once the door opens, remove the lockworks by taking the screws out of the side of the door and sliding the lockworks out.
First,. those characteristics will show up more and more as the cured item is exposed to warmth (from the air, or even from just being worn next top the body, etc.)