Re-wiring a 15-91 is fairly easy and uncomplicated. I hate doing house electrical things but I can and have done it.
Read Rains tutorial in his blog and simply follow his instructions. I did the light too so it's no big deal.
You just have to use your intelligence and be careful. Also don't plug nothing in until you've reviewed everything and are sure it's right. Then plug it in to a circuit protected power bar.
Here's my thread on doing the 15-91: {
http://www.quiltingboard.com/vintage...r-t205360.html }
Joe