Have any of you guys ever seen a John Dickson Round Action double rifle?

I've seen them on boxlock actions, but not on Dickson's famous round actions.

There's one coming up at an auction in PA - a BP .500EX.

There's more info about it on my blog:

http://www.dogsanddoubles.com/2012/10/auction-alert-a-john-dickson-round-action-double-rifle/

Thanks

OWD