James was found guilty at Kingston Crown Court on Wednesday 17 November.
Investigating officer, Detective Inspector Joe Daly of the Homicide and Serious Crime Command, said: "Mr Paytak and his son were entirely innocent victims caught up in a violent feud involving rival parties.
"Today, Michael James has been jailed for life for Mr Paytak’s murder and the attempted murder of his son, Husyein.
"James drove the stolen motorcycle to and away from the murder scene. His pillion passenger carried out the actual shooting. The pair are believed to have been recruited in response to a shooting in Clapton earlier on the same day.
"Throughout the investigation James continually denied any involvement. It was only when he was presented with overwhelming evidence that he eventually admitted being the rider of the motor cycle.
"James then invented a theft scenario stating that he believed he was going to steal a quantity of drugs from a shop and had no idea his pillion passenger was armed with a gun.
"James will now face a considerable amount of time behind bars.
"Mr Paytak’s death was a tragic and senseless loss of life, which has devastated a family. The police investigation into this incident continues. We are committed to continuing our efforts to bring other suspects involved in this horrific crime to justice.
"Anyone with information is urged to contact the incident room on 020 8345 3734 or to remain anonymous, call Crimestoppers on 0800 555 111."
A second man [B] aged in his 20s was arrested on 1 October 2009 in connection with the incident. He remains on police bail.
A reward of £20,000 leading to the identification, arrest and prosecution of those responsible for the death remains on offer.
Anyone with information is urged to contact the incident room on 020 8345 3734 or to remain anonymous, call Crimestoppers on 0800 555 111.
In a family impact statement read out to the court on sentencing, Mr Paytak’s daughter, Elif Paytak said: "Our dad was a wonderful person- he was always a happy person and never complained about anything. He was a down to earth person who loved to help anyone in need.
"Our dad was very easy going and loved life. He was a beloved husband and the best dad that you could ask for. He used to love spending time with his family, which was his favourite thing. When he wasn’t working he used to spend time with our mum Ayse Paytak.
"Mum and dad were married for 30 years and they had the best marriage, they hardly argued and loved each other to bits.
"Our dad was like a close friend to us, he wasn’t the typical strict dad. We would talk about anything to him. Our dad used to love socialising with friends and family and loved to joke and have a laugh. We have been a very happy and peaceful family.
"Since dad has passed away we have not been the same. It wasn’t just our dad’s life that was ruined, but all four of our lives. There is not one day where we haven’t thought about him. Time has not made it any easier and in fact it is getting harder to come to terms with as time goes by, because the truth of him not being around becomes more and more obvious.
"Everyday we wish that this was all a nightmare and we would wake up with our dad next to us.
"Mum cries everyday and hardly leaves the house. She does not socialise any more and all she talks about is dad. Sometimes she has no willpower to get on with life but her only strength is her three children and her grand daughter.
"I have lost hope in life after my dad was killed for no reason.
"The only thing that keeps me going is my daughter who is now five months old. My daughter was never given the opportunity of seeing her grand dad.
"Every time I look at my daughter I remember my dad as he couldn’t even see his first grandchild. How much he would have loved her is unquestionable.
"After my dad’s death I don’t remember being happy and I don’t think I will ever be as part of me has been ripped apart. I don’t even see my friends any longer as nothing feels the same any more. Our life has been shattered."