Ghostrider: Please see https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=561090&page=1

another image of the Parker



Unfortunately I have no details, but it sure looks like a thin lateral barrel wall blow-out.
As said on the other thread, expertly done sleeving is great; inexpertly is not - aesthetically or regarding safety.