A statement from Mr Mellor says he is making good progress.
He is thankful for the support he has received from around New Zealand.
"I hope at some point I will be able to thank you personally or through other communications channels."
Mr Gibson says those messages of support have been a boost to Mr Mellor, his family and police.
"Bruce is by nature a humble and private man. He's overwhelmed by the hundreds of cards and messages of support he's received."
Mr Mellor was attacked after stopping a Mazda that was being driven erratically near Taihape on December 11.
A passing motorist found him lying in a pool of blood.
He was rushed to Palmerston North Hospital with multiple skull fractures, broken teeth, a broken eye socket, broken jaw, cuts to his arms and a badly damaged finger.
An 18-year-old and a 14-year-old appeared in the Wanganui District Court this week charged with assault.