Those machines were not at all uncommon. However, they were treated as classified items for a VERY long time after the war. (The "Ultra secret" wasn't officially declassified until some time in maybe the 70's, if I recall correctly.) Retreating German military units undoubtedly destroyed a lot of them to prevent them from falling into enemy hands, but the Allies must've policed up bunches of them by the time the war ended.
For those interested in the whole code/cipher business, google "venona" for some interesting information on our codebreaking efforts against the Russians.
