Not quite fabrication but the project is in line with the spirit of the thread;
I retrofitted my old Milwaukee 18V Flashlight to accept an LED bulb today.
I purchased the LED upgrade bulb a few weeks ago only to find it didn't work. I looked closer and found that it works in every single Milwaukee flashlight made since mine, (but not including). The newer units all use a circuit to reduce the voltage for a 5V bulb where my old one is the full 18V right to the lamp.
I ordered a trigger assembly for one of the newer ones thinking I could rig it somehow but they took 2 weeks to send me the wrong part.
I happened to have an extra hard wire kit sitting around for my dash cam that is 12-24VDC to 5VDC so I tested it this morning and it worked perfect so I opened up my flashlight and transplanted the small power supply inside the handle and sealed it back up. Total time spent, 35 minutes.
Works like a charm and it only cost me $5, (plus the cost of the LED bulb).