Yep that's correct Rich, I could have driven it away today as it still has a valid ticket. However as soon as it leaves the station then it will require a full retest (unless the failure falls into a category of minor failures listed on a gov.co.uk site I was browsing earlier) unlike it used to be where they would just re-check the failure points.
Yes you do still get the forward dated ticket if presenting you old one with a month remaining.
Here's the list of free re-test items:
http://www.motester.co.uk/retest.htmlThe main site has some interesting info on the new computerised system.
It seems that the tester is logged on while carrying out your test and the system logs all details including how long the test takes. The benchmark figure is 50minutes and if a tester constantly conducts tests in under this they are likely to be investigated. Sounds like they are really clamping down on the mot industry.
Totalled up my bill and including the test it looks like I'm in for about £600, mind you I pity the poor sod that's got to change that downpipe.