I posed that question to Bob Gurr, designer of both the Viewliner and original Monorail trains, who was once a surprise cab visitor when I was firing. If I remember correctly, he said Walt had offered to donate the trains to (I believe) the City of Los Angeles to run at Griffith Park, but complications arose and the plans ultimately fell through. Another story which makes the rounds on the Disney circles was that they were offered to Walt's hometown of Marceline, Missouri if someone would pay to build tracks, and nobody stepped up to the plate. In any event, the consensus seems to be that they were ultimately scrapped after lingering in a storage yard somewhere or another.