Dear John,
you may be right. The first one was just in the center point of an inflamed discussion on ship modelling boards in Germany.
Like him or not (I dont know him, as I previously stated!) He is in business and sells stuff...and obviously has the EMMA.
On his site it clearly states GFK (=GRP).
Not sure of what "vintage" your experiance regarding the second one is, however, the old man retired a couple of years ago and the buisiness got taken over but operates under the same name. Again, I do not have any personal experiance with the new Owner, Jorg Brennecke, but he is known in the community and has expanded the business to quite an extent and builds display models for shipyards and shipping companies. Could well be that that is his prime field of buisiness and the retailing is "on the side". It seems he now has a proper web shop now (new)...
Indeed, his hulls are mostly made of Polysteyrene by means of thermoforming, a material and methof which is wide spread in the modelers world.
I am sorry to hear that you have had bad experiance with both of them...
Cheers,
Lars