These LUL tube trains are 1983 stock... Read about them
here and you'll discover they were the Austin Allegro of the London Underground, so notorious for unreliability they survived in service for a fraction of the time of others, barely 14 years, comparative to the 40 odd years, the likes of which the Victoria Line '67 stock has lasted. Given their reliability issues and narrow single doors, they were canned when the Jubilee extension opened, being replaced with 1996 stock.
They are kept in a VERY secure Layup yard, with a full security setup, including PIR poles, cameras, huge fences and a very high tech electronic access system, designed primarily to protect the 'in service' trains kept there after 2am, from vandals. As such, our 'jaunt' into the yard was undertaken in a state of perpetual fear lol. It was a case of get in, take a few photos(eyes darting all over looking for a reason to pissbolt out) then... pissbolt the fuck out!
The trains are knackered, i think from when they used to be layed up in an unsecured siding near Cockfosters, but despite being mostly destroyed, they still had the classic oldschool plaid seats, the ball handle grab straps and system maps of the pre-1999 extension Jubilee line.