Here's one I just picked up in a box lot. It is similar to EIN  (F‑Skirt) BROOKFIELD (R‑Skirt) No 41 SB, but this one has a dome number. The current Price Guide does not list the No. 41 with a dome number. In fact, there are only four listings with dome numbers. One has SDP, and none have No. 41 on the rear skirt. This piece is somewhat similar to EIN  (Dome) [#] (F‑Skirt) BROOKFIELD SB not only because of the dome number (a backwards 5 that shows upside down in this pic), but the color is Teal Aqua, which is not a color listed for EIN . I will admit that the dome number on this piece is a bit faint, so it may actually be an incomplete blot out, but it's clearly there, and either way it appears to be unlisted as the Price Guide doesn't list a blot out on the dome or a dome number for a No. 41.
I actually had another CD 134 Brookfield No.41 in my collection (not shown here), so I looked closely at that one, and while it is a different mold overall, and the color is Green Aqua like EIN , there is also a backwards 5 on the dome of that one, although it's more faint than the one shown here.
See [id=612323994] for closer views..
Update: Confirmed. This is an unlisted embossing that will be added as a new EIN listing.