I bought a new RT pannier back section from Motorworks and then swopped the lid, lock, etc from my original left side pannier. The lock is held in with pop rivets, just drill the heads off and remove the lock then rivet it into the RT back panel. Yo will need to make a bracket to locate the new pannier on the back of the foot rest bracket. I used a couple of flatpack furniture blocks bolted through the case, been using it for the last six years or more without problems. I also went to my local boy racer exhuast shop and got a piece of stainless pipe bent and a bracket fabricated to lower the can, cost £40. These days I just run with the cat and stubby.
thanks very much hank,will be speaking to motor works monday,i have some stainless pipe in workshop and my lad is a demon with a tig welder and enjoys making pretty things