Typically, there were three parts. The first was a gasket (originals were leather I think), then there was a bezel that was typically thinner on one side than the other(depending on the angle of the wiper post to the cowl) and then a nut to fasten everything down.
The bezel could be the same height all around if the wiper post is 90 degrees to the cowl.
The only thing I have is a manufacturers' drawing of the set up on an early Bird
As far as the sunvisors are concerned, the comparable US Victoria or conv. sunvisors may be the same.