Matt
I remember seeing a TV program that was a mechanical version of time team and they did either an M1 or 2 up in the REME workshops. All was fine till someone decided to test the seals luckily with a hose not the oggin and they discovered that had a lot to replace most had failed / perished so may I suggest you test them if you have not already as it would be crying shame if it went glug glug.
Have fun
James
