I'm really not sure what to make of the marks, but do note that in the Charles Twinam case, the seizure included ink stands dated for 1777. Twinam was also noted for using a 'WS' stamp, albeit with a central pellet.
Jackson, sorry if I appear over-critical, but can you achieve some sharper images? Those shown do not appear to be made with a camera using a macro feature. Really sharp images are essential if we stand any chance of cracking this riddle.
Further information regarding Charles Twinam can be found at:http://www.925-1000.com/a_OB_Twinam1899.htmlhttp://www.925-1000.com/a_Spurious1899.html
One detail that goes against any involvement with Twinam, was that much, but not all, of his forgeries contain a Leopard's Head mark with a flatter base than those shown. But of course, there were many other counterfeiters around besides him, but let's keep an open mind in the hope of clearer images.