Years ago I dismantled a Baron, undid every nut, bolt and panel and as a result ended up with lots of good bits such as this interior Grimes Light fitting.
By replacing the 28 volt aircraft quality bulb with an everyday 12 volt car bulb, and the making up a mount plate, along with a simple switch mounted on the overhead section of the number two fuselage frame, bingo interior lighting for when sleeping outside is not going to happen!
To try and do a simple item like this with the fuselage skins in place would be much more difficult, so I see these things as an investment in time saving.
It may not be high tech and modern like some of the new light weight L E D lights that are now available, but there is something about the old world fittings that has some nostalga value plus it's a feel good thing about recycling!