I have travelled in Spain. 100's of trains change gauge from Broad to Standard without stopping each day. you just need changers at Belair and the Interstate for flexibilty. These are readily available and can be installed with minimum disruption Travel time after this happens will be much longer than the bus. Express trains take an hour non stop from MtBarker junction to the Interstate terminus. The line is single track and long freight trains can run in the peak hour limiting train paths. If you are doing that, at the same time put in a gauge changer at Dry Creek and run a commuter service to stations to Two Wells