73 duster gauge bulb socket / holder?

Had a gauge bulb out. I was very careful but still broke the little tabs off the bulb adapter to the dash. It's the little 158 bulbs. I went to Napa, O'Reilly, autozone. I gave up looking for that little black adapter. I see a few on eBay, but there's no description of the size. Plus they are a kit with LED bulbs. I plan to just run the 158's. What do you call those little black adapters and where the heck can I order them. Google isn't bringing up any helpful suppliers.