When I acquired a Syers (pat Wilson Riley) for next to nowt I incorporated it in my v slowly built workbench (it's mine on the excellent smallworkshop site) - very pleased with it, especially as it's about 140 yrs old - this one is rack and cam, with no small part to lose. I have since acquired an Entwisle & Kenyon (US licensed to Massey) patented only a month or so later - not yet fitted to anything - but I should mention that the end of the cast iron knob is broken off. I also found an engineering version of the E&K - in this case it looks like the end of the knob has been walloped out of shape (must have been up-graded to wrought iron, not cast?) --- this shows what these vices are not for -- a very tight grip, eg if bashing metal. But they're really great for a quick grip for most applications.
Why were the hillside towns to the north-west of Bradford such a centre of vice inventing and making?? Riley, E&K in 1870s - and then five years later the big one - Parkinsons (the precursor to all Record, Woden, Para. etc) and at least one more maker - all within view of each other on a clear day.