Just be aware that any accreditation you may have for Newport or Manchester is probably not going to be worth anything.
One would assume that having trained for accreditation, you would be able to re-test at a different track with minimal tuition..?
The theory is that your current Manchester/Glasgow/Newport accreditation should be valid – there was a recent agreement that all indoor velodromes should recognise each others accreditation.
However their website appears to contradict that in places. Probably worth a call to them to clarify but be aware that, like Glasgow, the first few months of public sessions are likely to be accreditation rides simply to build a pool of riders to start running training sessions, races etc.
In fact, see here:
http://www.visitleevalley.org.uk/en/content/cms/london2012/velo-park/track/track-accreditation/
where it says that if you book onto an SQT you have to turn up with written proof of accreditation from one of the indoor UK velodromes.