Someone posted a while ago they did import from vb4 only it didn't carry attachments.
There was an exchanhge re working on that.
Try searching on: import / vb4 / attachments.
Doh!
Ive been racking my brain trying to find the import script.
Thanks for the help guys.
Ive figured out most of my issues (mostly by drinking a cup of coffee to wake me the f up, and starting back from square one).
I can confirm that everything except attachments, custom user profile fields and vB subscribers (aka XF upgrades) was imported smoothly and accurately from vB4 => XF using the 3.7/3.8 importer.