Is your heirloom pin sitting in the jewelry box because you're afraid the mechanism won't stay closed and you don't want to risk losing it? I know I'd rather not lose my pin but it's a shame not to be able to wear it. If this is the case for you I have a trick to share!
Go through the fabric once and then twist a rubber earring back onto the pin. Then push the pin through the fabric again and fasten. The rubber stopper will prevent the pin from falling off if it happens to come unfastened. You can find rubber earring stoppers at most craft and jewelry supply stores.
I hope you find this helpful! Have a wonderful holiday!