As I understand it, Richard Ellis's Patent refers to the ingredients of the solder used in the close plating process. I am unsure of what Samuel Colmore's Patent was issued for, but it was certainly issued much later and with the advances in this ever growing trade in the search to bond silver to steel, I would suspect that Colmore's Patent was also to be regarding solder.
I had not heard that Colmore's Patent shut out his rivals. I wonder if this thought is rooted in the fact that so few Birmingham manufacturers registered, as required, at Sheffield. Although, I'm sure, there was a reluctance by Birmingham makers to be ruled by those of another city, the real truth, I believe, with the exception of the real big guns eg. Boulton and a few others, is that there was little in the way of manufacture of the products that we associate with 'Sheffield Plate' carried out at Birmingham, the trade there was mostly confined to everthing in the small line, buckles, cutlery, jewellery, buttons, etc.
As for the rush in 1807, again, I can only guess, that in the preceeding few years, with technology and demand advancing, more makers entered the market at Birmingham. Perhaps this, in turn, prompted a clamp down by the guardians at Sheffield, and with the threat of a Â£100 fine, caused an influx of registrations at Sheffield.
Does the above fit in with your thoughts, or do you have a different mindset on the above?