Re: Converting D class NY state license to Class D in Zurich?
When I converted my "regular" US license to CH (in 1994) it came back with endorsements to drive things much larger than standard passenger vehicles. I subsequently converted the CH to Norwegian, and back again, never being questioned if I was properly qualified to drive a lorry or bus.
This is not a very useful answer with a good weblink, but unless you foresee a future use for the extra endorsements I wouldn't waste any time trying to figure it out - potluck, see what you get. I would be surprised if letter categories have a parallel conversion from US to anywhere in Europe, or rest of the world for that matter.