Geoff,

Regarding your description of the Schuyler, Hartley & Graham mark, I would agree with your comments.

Regarding your description of the Sinclair, Hamilton & Co. mark, I would also agree with what you stated ... but add a couple of additional points, based on my experience and observations. The first is that the SHC mark can appear as either as Crown/S/HC or it can appear as Crown/SH/C. The second is that there may or may not be a small horizontal arrow associated with the SHC mark. Sometimes it is seen with the arrow, and sometimes it is not.

Mike