Eurail.com sells Paper Passes: Global Passes or One Country Passes like BeNeLux or German Rail Pass, but they need a long time to get shipped. You should be able to buy it also at the international ticket offices of the railway companies in Germany DB, Belgium SNCB/NMBS or Netherlands NS. Keep in mind that high speed trains Thalys needs a reservation to be used. ICE trains have only optional reservation that can be done via seat only option of bahn.com.

Rhine Pass never heard before.

I actually meant the German Rail Pass.

German Rail Pass is now for anyone-not like EUrail only for non-continentals- and for sale-only as paper!- at ANY major DB=german station, incl all at main airports. ON the spot without much waiting.

BeNeLux is for most not very useful, certainly not if you are ju/senior, as lower local fares are available to them. LUX is free, and in BE only Brussel Zuid+Midi will sell it on the spot.