Thanks for the superb help again!
I've always seen a bunch of freightliner Class 66's at Ipswich station by the 'shed' which seems to be an office. But there never seems to be much going on there.
And just this morning i send an email to NXEA As i found out they have a depot in Norwich.
The travelling fitters is a new thing to me, but sounds quite interesting. I'll have to see if i can find anything else about it.
Thanks once again!