There was an auto manufacturer (just body + chassie maker) with the name "Grey..." or "Gres...". Does any one knows any company with that name?

Hi Telecolor, there was/is a coachbuilder in England that did hearse and limousine conversions of the British/European Ford Granada called Coleman-Milne, that had a model of limousine based on that car called the Grosvenor; is this something like you are thinking of maybe?
Just google "coleman milne grosvenor" and hit images; lots there!

Max

I forgot to tell that I found the name: "Gerstenslager".

Ah, Gerstenslager. Known here for their trucks that served as Bookmobiles, delivery vans and TV station remote vehicles. Here's a history:

http://www.coachbuilt.com/bui/g/gerstenslager/gerstenslager.htm