The remains of a man found buried in a remote forest in Conwy county three years ago are likely to have been left there between 2004 and 2010.
Detectives found fabric from a jumper sold between 2000 and 2004 and a label for Marks & Spencer underwear from 1999 to 2000 near the site.
The remains were found three years ago during a Wales GB Rally Stage when a spectator discovered part of a skull.
Despite repeated appeals, the man has never been identified.
A post-mortem examination previously revealed he had been murdered by a blunt trauma to the skull, and examinations of his teeth and specialist radio carbon dating found the man was born before 1950.
Det Supt Iestyn Davies from North Wales Police said: "We are prioritising the period between 2004-2010. I stress, however, that this is our priority period and we are not ruling out that the victim was left at the location prior to 2004.
"Based on all the evidence collected we have a really effective means of eliminating names put forward in this case and would therefore encourage anyone who thinks they know the true identity of this man to come forward."