Unfortunately, in that era, every manufacturer was doing their own thing, much as they still do today. Even though different manufacturers used similar designs, they are each unique, with the exception of a few standardized parts from common sources such as tires, batteries, bulbs and chains. Handlebar sizes were somewhat standard, but even then, each company made their own throttles, switches, lever assemblies, etc. Even when manufacturers used the same third party for things like forks, brakes, shocks, etc., they normally used some unique variation, such as mounting, bolt and axle size, length, and many other dimensions. A few parts may be able to be interchanged, but usually require some modification.