All joking aside - In my case, it could be any razor I use. Hopefully, it'll be my whole collection including hones as no razor I own has any family history other than that which I make.

What's more important for me, would be to teach my kids to respect those razors I have loved in order for them to keep em after I die... Moreover, hopefully that respect will be passed on to their kids in order for it to indeed become an heirloom.