Re: Lighting Coil?
It's just a square spool that could be made from plastic or even cardboard that's been varnished or any other method to make weatherproof... then you need to wind it with the right gauge wire and optionally put a steel or iron core inside the opening in the spool... this would be real easy to make and wind with a round plastic bobbin, but you could make your own square one and make some kind of adapter so you can use a cordless drill to do the windings.
If you can find out what wire gauge he was using and how many windings are needed, this would not be hard to make at home.
Maybe try and find an old transformer that you can open up as these usually have square shaped spools that the wire is wound on. For the wire, my guess is 20 to 24 gauge wire and 10 to 12 wraps should get you close... we used to make our own coils for tattoo machines by making a holder for the spool that was then chucked into a cordless drill, the cordless drill works really well because it's easy to control the speed so you don't go too fast and break the fine wire, but not so slow that it takes forever to get enough windings to be effective... the windings do need to be neat and go across the spool tightly which makes it easy to keep track of how many wraps you have, one wrap means one layer or wire wound the length of the spool, and it can take anywhere from 6 to 18 wraps depending on wire gauge to get a good enough voltage and current to run the lights, you will want the voltage to be strong enough at idle but also a way to regulate it so it doesn't burn out your lights as rpm goes up. There are several methods of regulating the voltage, either by using a moorcycle or moped regulator or making up a solid state type... either way, this will take some experimenting to get right unless somebody knows the wire gauge needed and the number of windings to do. You shouldn't have too much trouble sourcing the magnet wire, and if you can find a transformer supplier you may get lucky and find the right size spools so you don't have to make them too.
I can help some with the electrical stuff but others in here may have better ideas on how to make a dependable generator that will give enough power at idle but won't fry your lights at rpm.