I was helping someone clean out a garage today and ran into these two [020] Armstrongs. Nice olive tint. One of them had the black plastic insert, and the more I thought about it I couldn't recall ever seeing that. I have seen the potmetal or lead ones, or whatever they are...just not plastic. Common? Way common? I should get out more often?

Btw...The sweet Harley oil cans were sitting in a box in the corner, unopened. Some were bent and too corroded, I got 7 decent ones. The lady said they were already old and in the same box when she bought the house in 1970.

Update: Apparently these are quite common, and have been found in colors other than black. Thanks to Bill O. And Don W. for the informative emails.