Speaking of pooling collections... I'm not ready to supply a streamlined, sorted list just yet, but I have made ready reckoners for myself which show every player by season for "The Avengers" (be warned, they can have up to ~ 600 images each):
Season 2 : Cast
Season 3 : Cast
Bear in mind they're not intended for public consumption and may be a bit broken here or there (I generated them with a script and haven't checked everything went as planned properly). they're cross-referenced with my pages for regular guest actors and appearance in a few other productions (Dr Who, Danger Man, The Saint, etc...) The cross-referencing is a bit out of date for Seasons 1-3 as I've recently gone through those, aided with camera scripts, and identified a whole bunch of additional extras, who are often credited in the script but not on screen.
I'm about to launch bigger 250x250 images for Season 3 (and maybe even 500x400 copies), as soon as I finish recapping the last three episodes, so watch this space...
Got myself in a muddle over Bob Raymond, Richard Cuthbert and another craggy gent in the process though... Richard is a short bald man with alarming eyebrows, yes?