Vintage Zinc Mason Jar Lids with Boyd's Genuine Porcelain Inserts

Wonderfully aged zinc Mason jar lids. There are six, one stamped on the top with Atlas, two with Ball and three unmarked.  They could be as old as later 1800s to about the 1940s but I've managed to date the two Ball ones to about the 30s so most likely all of them are close to that.  All of them have white inserts, two of which appear to be the faux porcelain common anywhere from about the mid 1800s to the mid 1900s and marked with "Genuine Boyds Cap for Mason Jar". The other inserts feel more like old plastic to me though I could be wrong about this, I really don't know and was unable to find out from my research. These are unmarked in any way. The inserts were bought separately from the lids so they can be a mix and match of dates and eras.  So intriguing!
Lids is about 3" in diameter.  Listing is for all six and included in this at no charge is a vintage glass lid insert marked Mason and with a J. Has the rubber seal. I just had the one, it was with the lids when I got them, seems silly to list it on its own! So my gift to you!

Excellent vintage condition. For their age an what they are. All show signs of life and use.

Please note that many of my items are vintage and/or made using vintage materials. I do my best to list any major issues but some signs of life and love are to be expected and only add to their charm.