Good ol' youtube has some videos of the museum operation, one of which I posted here a while back. I'm pretty sure the operating end of things is all 60cm. I'm guessing the original equipment may have been left over WW1 stuff. I think, like evidently a lot of 60cm lines in Europe, they were primarily built for transporting agricultural products. Sugar beets seem to be a staple of an awful lot of narrow lines "over there".
Looks like a classy operation!