Not quite my heirloom. but the Mk2 Airsporter I picked up at auction last year should have been someone else's.
It had clearly been looked after very well over the years, it's bluing is almost A1, the stock is lovely and it's got the foresight hood which was knocked out of it's grooves and went back immediately with a vintage skinny Japanese Nikko sterling sight which looks to have been with it all these years.
I wonder whether it's owner died and the family for whatever reason got rid of it by the easiest means.
It does not seem right to change it in any way, except for sucking Neatsfoot oil through the transfer port and letting it stand upright for couple of days.