Very cool Baz!
You've got quite a collection of them going-
My big brother's 83 has stock mufflers too, when the originals rusted/wore out he insisted on another set even though the parts guy at the local Honda shop was suggesting aftermarket set ups that were a lot cheaper.
He loved the way is sounded and didn't want to monkey with jets or settings... they do look and sound very good
Rebuilding the carbs after it had set for too many years returned it to a smooth idle and good response