Robert_Charlton - 9:30 am on Nov 13, 2012 (gmt 0)
Jez, if there has been no additional promotion of brand.co.uk (ie, links built to it and redirected to the .net), I'd go for it. People pull domains out of 301 deep freeze all the time and thaw them for re-use. Again, watch the new link building, particularly the rate of build. Use the Google Historical Links patent as bedtime reading.
Good luck, and please keep us posted. The vicarious thrill will keep us going. ;)