Clive Feather:
I was reviewing something and realized I was unsure about the
Stonebridge Park closure in 1999. Here's what I currently have:

Fri 1999-10-22 Last day of normal service.
Sat 1999-10-23 LU trains turn back at Queen's Park. Silverlink run a
shuttle from Stonebridge Park to Watford Junction.
Fri 1999-10-29 Last day of shuttle service.
Sat 1999-10-30 Stonebridge Park station closed for building work.
Mon 1999-11-01 Line reopens to both LU and Silverlink, but with
Stonebridge Park closed and trains non-stopping.
Wed 1999-11-10 Stonebridge Park re-opens.

Does anyone disagree with this?

Underground News does. This is covered in the December 1999 issue.

The first thing is that UN gives the first date as Friday 1999-10-21,
but since there was on such date, I think we can assume Clive had
that one right!

My other question is what happened on Sat 30th and Sun 31st: were there
simply no trains at all on Silverlink, or did the shuttle run from
Watford Junction to Wembley Central?

UN merely gives a southern terminus of "Silverlink Metro services".
If this means trains to Watford Junction, then the answer is that
they ran from Watford Junction to Wembley Central on *both* weekends,
the 23rd/24th and the 30th/31st, but were extended to Stonebridge
Park from Monday 1999-10-25 to Friday 1999-10-29 inclusive.

It also says that Silverlink County trains made extra stops at
Queen's Park and Wembley Central during the work. I suppose those
were on the main line.
--
Mark Brader A real Canadian science-fiction plot would be
Toronto about whether alien visitors were a federal or
a provincial responsibility. --Duncan Thornton

My text in this article is in the public domain.