Johnson, Baxter, Morrison, Chuter and Moody were present at the HAC in the City of London, while Walkinshaw - who passed away in 2010 - was represented by Ryan, currently the majority shareholder at Gloucester Rugby and former Gloucester Managing Director, Ken Nottage.
Ryan was disappointed his father was not able to accept the accolade in person, and remembered how his childhood was shaped by rugby.
"It is a huge honour," he said. "Obviously it is my father who is getting recognised so it is a bit strange we going up and accepting this reward on his behalf, when it is an award that he should really be receiving himself.
"But at the same time for our family it is something that we are hugely honoured by.
"For his efforts over his time at chairman of Premiership Rugby and for everything he did with Gloucester he is being recognised and remembered in such a wonderful way.
"His passions growing up were always cars and rugby and he played rugby and raced cars - it was a perfect combination for him."
Ryan grew up as a Gloucester Rugby supporter, courtesy of Tom's influence, and he is dedicated to ensuring the club returns to Europe's elite.
And he knows the legendary status held by Kingsholm and The Shed is an important part of the club's history and future - and something that will continue to play a huge role in its success.
"I grew up as a fan of Gloucester from the age of ten years old, going to nearly every single game with my dad - it was where we spent most of our quality time together. It means everything.
"Fortunately I have been left a club that is in good shape. I feel we have managed to make some huge strides forward in what we have done with the club and hopefully we are putting everything in place to have a more competitive team going forward."
The Premiership Rugby Hall of Fame - supported by British Airways and Heathrow Express - raised money for both Sport Relief and The Supporters Club.