The Masport Olympic reel mower made by Steelfort N.Z used a centrifugal clutch running a Tecumseh and I think Briggs which worked well enough. Then they changed to a twin cork clutch set up. Before that the Masport Morrison reel mower also had a centrifugal clutch, which was identical to the Victa one mentioned by Darryl ( as far as I can recall ) I only remember seeing 14'' Victa"s with a 2 stroke on them.
You may be able to purchase the centrifugal parts from Masport and modify them to suit your Rover 45. But would it be worth all the effort? The only issue I have ever had with the 45 top clutch is them coming loose or going out of balance. They should of never got rid of the cast iron ones.
