this is what happens when things are privatised - lots of talk but not much action! Rather than inconvenience thousands of people every weekend, why can't they inconvenience themselves and do a bit each night after closure? They could then perhaps just close one day at the weekend.
the new moving block signalling they're installing will greatly increase the frequency of trains as the trains will no longer be 'driven' by the driver but will work in a similar way to the DLR (Docklands Light Railway) where all trains are driven from a central control room; the driver will only intervene in an emergency. I recently had a trip on the Jubilee on a 1938 stock train and that was the last time that particular stock will be able to run as once the new signalling is complete only the 1995/6 stock Jubilee line trains will be able to run.
Please excuse my ignorance re the London Tube, but I now live in Essex and my visits to london are few. When I do go I never need to use the Jubilee Line, but have not come acrross one of the old 1938 stock on any other line I've recently used. I was pleased to hear that they are still in operation though. Are they still operating on other lines as well as the Jubilee and I've just not been lucky enough to see one? If I'm not already too late I would love to ride on one of those again before they disappear forever. When I lived in south-east London as a child back in the 1950's I was a regular user of the tube and have fond memories of the characterful old trains that used to take me from stations such as Kennington and Elephant & Castle to wherever. I can still see in my mind's eye some of the old adverts displayed, one being flights to Paris with B.E.A for seven pounds return! A week's wages for my dad in those days!
sadly they don't run the 38 stock routinely any more. The trip I went on was a special commemorative tour organised by the London Transport Museum.
I believe that the museum is organising a similar trip at some stage in the not too distant future on the Northern line so this would certainly take in the Elephant, Kennington, Borough but you would need to check their museum - www.ltmuseum.co.uk - or perhaps give them a call and ask that they take your details down. the trips sell out quickly as there are plentty of enthusiasts who snap them up.
The 38 stock still runs every day on the Isle of Wight railway. However, they have been slightly modernised and so aren't true 1938 Underground stock.
You should definitely look at the LT Museum's trips schedule. The posters/adverts that you refer to are plentiful and advertise 'well paid jobs' with London Transport as ticket office clerks and suchlike and by the time you get off it feels as though you have just fast forwarded 50 odd years!