Hi Norm, It is an interesting method of trying to drive an LED while limiting current. If the stepper motor is properly selected it would likely work to some extent as the output from the stepper would be limited. The light would flicker out at the top and bottom as the motor stops to change direction, and the whole thing has a few mechanical parts, the failure of any one would cause the light to fail. What current are you aiming for and approximately what voltage?
By the way, the batteries that you built from the bruce packs are all installed over in the Philippines, and at some point Bruce or I will post a story on that trip. We got 41 kits there, and installed about 23 of them that we were able to get through in our limited time, we had our trained team of local installers install the last few save one, to ensure that they could get the rest of them up without our intervention. Jerrick, our guide out in the boonies, wrote me that the remaining 18 have mostly been installed at this point. Rich