Hello Andy:
The RAF's Bomber Command webpage indicates that the Command's Feb 45 attacks made up of forces like those which carried out the Worms attack were made by No.'s 4, 6 and 8 Groups:
http://www.raf.mod.uk/bombercommand/feb45.html
In other words, attacks in Feb 45 made of
about 300 Halifaxes/30 Lancasters/20 Mossies were made by No.'s 4, 6 and 8 Groups.
This could be a useful lead, while working through the files.
Good luck
Don (Boomerang)