Well, well. Look what I found.
Tucked away on the Focus Features web site (buried under miles of Flash, but somehow a search for “tinker tailor soldier spy conference room clock” got me there directly): the screenplay for Tinker Tailor Soldier Spy. By Bridget O’Connor and Peter Straughan, and nominated for a Best Adapted Screenplay award.
P.S. I am sure that many fans will be glad to know that the shooting script gives Guillam’s boyfriend a name. You’re welcome.