Here are all the Czechoslovakian athletes that competed at St.Moritz 1928 :
By nationality:
The four Germans are from the "Sudetenland". The German-speaking population of this territory was expelled in 1945. Although Czechoslovakia did not lose any area at that time, it did lose part of its population. The athletes from that group should follow the nationality that their descendants would get (and in fact they themselves also got).
This page is part of the site "Full Olympians" by Herman De Wael. See here for a full Introduction.