Yes the everted edges of the locker orifice mate with the raised lid profile. This what you have identified.
Classic car body restoration suppliers have a range of hand operated bending gadgets which might do the fancy bits. For simple bends I have one of these. With care you can do a long run or dismantle for small pieces as it comprises 3 pieces of unequal lengths. Looks better than the vice marked metal on one piece & a "hammered effect" on the other!
http://cgi.ebay.co.uk/150mm-SHEET-ME...item2c592c4d93