Sort of answering my original question -

In the book "The Met & GC Joint Line" by Clive Foxell, he states that if
a Chiltern train arrives 3 minutes late at each end of the joint line,
it will be held until the next slot is available. However, if a Chiltern
train is held up by an LUL train, then Chiltern receive financial
compensation. The book also states that ticket revenue from Amersham to
Harrow is shared. For onward travel, two sample checks of tickets are
made each year to calculate the share of revenue. This book was
published in 2000 and perhaps something since then has changed, but
certainly the automatic barriers must now help in calculating the share
of ticket revenue.

Can anyone confirm this is still the case?
--
Matthew P Jones - www.amersham.org.uk
My view of the Metropolitan Line www.metroland.org.uk - actually I like it
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