Terry,
If they are truly the original bushings, they are insulated with rubber. The much superior design (at least in terms of longevity) with asbestos insulation was adopted with the '33 models (and have 40-prefix part numbers) and became the service replacements for the original '32 bushings. It also seems as though while there were all manner of replacement bushings offered as aftermarket parts, only Ford provided the superior asbestos-lined versions. All of those rubber-lined bushings were doomed to failure as the rubber aged and the weight of the car overcame the molecular memory of the rubber used as insulation.