See previous pic for longer explanation.

Here you can see the 16? has a wire groove more similar in width to a 164, but the skirt area itself is still a lot smaller that either of the other two in the picture. Note SDP versions were used of the 164 and 162.1 to make a better comparison. A SB 164 and 162.1 are way off of this 16? for heighth etc. I do not know if the 16? comes in a smooth base, but seeing Brookfield did not like making drips, I have to wonder.

See next picture - Tom Nielson found a SB version.