#2057's have the filaments wired up opposite of the 1157's,so if you swap one for the other you'll still have lights--but being "reversed" the wrong filament will light up instead of the correct one....................................................................................................Most forigen cars use two 1156 bulbs instead of one dual filament one for tail and brake lamps,and they require a converter to work with trailer lights if you tow,being wired differently............................................................................................At one parts store I worked at that has been in bussiness since the 30's under various owners and names,still has a cellar and attic with lots of old parts still new,in dusty old original boxes..when I worked there I came across a whole rack full of old 6V bulbs,some were for headlamps and used before sealed beams came about--my boss sold a box of AC-Delco ones for 100 bucks for the box,ten bucks a bulb,to a antique car owner who often sold parts at swap meets..boss thought he made a killing,but the guy confided in me he could get 20-25 bucks each for them from guys wanting to win originality contests at high end car shows...even AC sealed beams with the period correct lens code can sell for 100 bucks each to the person who needs them or wants his car 100% "original"......
