This is Eric. Heidi can explain. The bulb base contacts can be removed if you cut or grind off the plastic holding down the metal circuit traces, so if you have a spare assembly you can pull a contact from it and add it to the one you want an extra bulb. You can trace the current path back to the right connection . Re melt plastic or use hot glue to hold down the trace you bent up for the install.
I haven’t explained that well, but should be obvious from the pics.
shooftie 
#1 by oldfussbudget on July 23, 2023 - 4:40 pm
Eric and Heidi as in Eric Caron?
#2 by albell on July 31, 2023 - 11:01 am
Yes