Found this conversation on a British Badges Forum, about "BP & CO Bham" Canadian badges.

To a question posed by Canadian Badge Collector Alan O. "Would a fake bother to put the "BP & CO" stamp on the slider (of a badge)?" Not sure what he's referring to by a slider. Perhaps someone more versed in badges could answer.

Forum member Nick Mugford responded "BP & Co Birmingham was a genuine mark but rather rare and has been faked." Not sure if this has any relevance towards the 1946 ring but an interesting note. Got more time tonight, will continue research.

Here's the convo, about half way down first page is the reference.

http://www.britishbadgeforum.com/for...hp/t-1809.html
http://www.britishbadgeforum.com/mak...arker_&_co.htm