I have seen those open circuit board ignitors, on the AEL NEMA head on eBay, although I had never seen it before. I was wondering if the circuitry, is affected by weather, since it's not enclosed on these. I would think it would get wet from water leaking in or condensation buildup inside the fixture.
It doesn't seem to affect them. I have a used Thomas & Betts 113 that I got from a local electric company several years back and the open board ignitor inside it still works fine. I think there is a date written on the ignitor of 1988. So it did like 25 years of service.