Nick,(posted 7999 days ago)I think you should read the info on this CML site:
www.cml.org.uk/servlet/dycon/zt-cml/cml/live/en/cml/pub_info_dept
Don't forget that this is a voluntary 6 year period. You say that they contacted you before the 6 years were up, so the aforementioned code unfortunately won't apply. The courts have yet to decide whether the limitation period is 6 or 12 years & when the periods run from. I would follow the good advice on this site. Professional advice can be obtained from the CAB or other organisations listed on the repo site.Good Luck.
Mark.