With my own eyes I saw what looks like the engraver amost engraved a D where the L of BROOKFIELD was supposed to be. In this close up pic I can see that the whole D was partly engraved before the engraver recognized his mistake. Maybe the same engraver had made the same mistake in the past and learned to double check his work before finishing the work. I say this on account of a pic Lee brewer add some time back. [id=380038245] on this link to see his pic. [id=382819414] here to see pic of the whole front of insulator.
By the way. There are a couple Brookfield ponies with spelling errors. Niether mine or Lee's is one of those.