Stop in for a cup of coffee
At the time, most folks considered the 6014 a better product superceding the 6012.
The disadvantage for A-bodies was/is the 18 gage wires (and long path with many connections) to the headlights now had to carry more current. That might have been upped to 16 gage for MY 1976, but it wasn't in '73 when Chrysler started using 6014 as standard equipment.
There was an website, Don's bulbs, for all sorts of older and obsolete bulbs. But he was closing down/retiring. Don't know who bought his remaining stock. Movie and slide projector bulbs probably are an important part of that market.
I bought a box of genuine 1038A bulbs from Stern some time ago. I wanted the real thing - and he hates them anyway - so it worked out well. Point is that he sometimes has older and obsolete stuff to sell.