Mizter T wrote:

This does all rather presume that Chiltern will keep stopping between
Amersham and Rickmansworth and at Harrow on the Hill - are they
obliged to do so under the agreement with LU?

Part of the regulatory requirements at privatisation is that there is no
degradation of service from BR days - the Passenger Service Requirement
(IIRC, it was a long while ago!).

There are already two
(morning) up and one (evening) down Chiltern trains that don't stop at
Amersham - though I understand they do actually pass through slowly
(for a trip-cock test?).

Two up that don't stop at Amersham and two more that don't stop south of
Amersham. Similar on the return (neither the 18:23 nor the 19:15 ex
Marylebone stop at Amersham).

This could be taken as suggesting a
begrudging attitude by Chiltern in serving Met line stations, though
I'd think it's just a sensible approach with regards to busy peak time
services.

They were additional services added in the mid-1990s to cater for the
increasing number of commuters from north of Amersham, rather than a
withdrawal of stops from other services. The only station that lost its
Chiltern services was Moor Park.