Hmmm, I'll take that as a "no" then. The aim of this was to replace two switches, one of which is always pressed (effectively SPDT), with one switch and a transistor, but then I realised I needed to catch the brief "in-between" state where neither switch is pressed since either switch can generate a pulse via the same circuit. (The version I attached creates enough of a gap) Think I should just go back to using two switches rather than start adding more components.
As always, thanks guys