Here is the legendary barrel which is supposedly fitted to the RGS exclusively. I don't believe this to be so for a moment.
It is completely buggered after a big blow, it is cracked through the base and around the bottom and through the pushrod tunnel.
I am not the guilty party, it was given to me some time ago and I believe it came from a gentleman who raced sidecars with A10 engines.
I met him back in the 60s when I was having trouble keeping barrels together and had a look at what he was doing to keep them together. His solution was too ugly for me, brazing pins from top to bottom.