That looks like any currently-available incandescent bayonet-based light bulb.
FI use them for instrument lights in Stewart Warner, Autometer and a host of other aftermarket instruments. I just built a 10 socket dash light harness for a '34 Ford hot rod last weekend using these.
They also fit the dash in my '55 DeSoto wagon.
They work in all side marker lights and can also be used to replace 1185 bulb sockets in later model cars.
Look for one of those HELP carousels at your local parts store and there should be a variety of the,.
Now, if you're looking for one with the bayonet stule male plug on the end of the wire, you'll have to start looking at Classic Industries, Year-One, Dante's, Kanter, etc for a reproduction socket.