If the lock is so corroded that the key breaks off, you can fix it yourself easily.
1) Mark 7/8" up from the tip of a 7/16"
Left-hand drill bit in a good 1/2" drill. Every garage needs a set of those!
2) Drill
very slowly right down the middle of the lock cylinder. Hold on tight! and watch closely, it
might unlock the cap in this process.
If you see it start to turn... Stop! and take the cap off. You're done. Go to step 5.
3) If that doesn't do it, keep drilling down to your mark (7/8", no more!) and blow out the junk thats left.
4) You should see a green slot in the bottom that a big flat head screwdriver fits in. Thats the slot you turn anti-clockwise, a wrench on the hex of the screwdriver shaft may help you turn it if the corrosion has gone that far, but most of it is plastic anyway.
5) Then go to e-bay and buy a gas cap for $10 and have it keyed. Win!
https://www.ebay.com/itm/03-10-BUEL...451229?hash=item2ac8f9f69d:g:GwsAAOSwl1xcVzq6
Don't worry about Lunatic, he's not mad at you. He doesn't understand that all caps is YELLING!!! He should try the bold, italic, or underline buttons (4,5,6 from the left) for emphasis to a point. People don't usually take well to being yelled at for a simple question:up: