Bob, if you look on Amazon (ok I know they don't pay their taxes / do exploit workers etc) you can buy a double dvd that has both the BBC Cheviot, Stag and Black Black Oil and also The War Game--- and it has them in two formats, Blue Ray whatever that is and ordinary that works in my elderly player.

I think you can also watch it on youtube.

And of course if you want to see a live production, Dundee rep are about to go on tour with their excellent version of the play which I saw - - was it last Autumn? --- check the tour schedule, they have a week ?) in Dundee soon, towards end of August and they finish in Citizens' Glasgow in early October (no availability left for that theatre) in between they are at Edinburgh Lyceum, Kings theatre Aberdeen, Eden Court Inverness - but I can't remember the order!
When I looked last week there were still tickets for Dundee and I think most of the others, just Glasgow sold out.
Alas the touring version is normal seating only (they had or stage/ part of the ceilidh when it was in Dundee previously)