It is a mystery to me why SMB does not use LEDs for interior lighting. I asked many times during the order lead up period... "we're working on that" was my bunk answer.
A good source for replacement 1141 (bayonet mount, single contact) bulbs for the SMB interior lights is: www.dav-electronics.com
The replacements DAV offered put out a great task, or spot light. Not a bright throw like the stock incadescant 1141. Even better, they are good for thousands of hours and draw a fraction of the juice.
FWIW, a quality product made in U.S.A.