In 1955 Doc is in the Delorian and is struck by lightning and sent back to 1885. Doc is stuck there because the Delorian broke. Doc hides it in the cave behind the cemetary for Marty and 1955 Doc to find to get Marty back to 1985 again. But Marty takes the Delorian BACK to 1885 where Doc AND the Delorian are stuck. Wouldn't that make 2 time machines in 1885 at the same time? Why didn't they just go get the gas from the Delorian Doc took to 1885??