Most likely Samuel Marshall.

Geoffrey Tweedale's 2nd edition Directory has some information on him:

Samuel Marshall may have been baptized in Sheffield on 17 May, 1786, the son of Martin (a cutler) and Ann. By 1822 he was listed as a pen and pocket knife maker in Allen Street and continued to work there during the 1830's.
There's a bit more, but it's all well after the period of that razor. I'd guess 1825-1835 for a date of manufacture.

I don't want to sound too certain about the manufacturer though. While some pen and pocket knife makers also made razors, it's not a given, and there may have been others named Marshall making razors in Sheffield who weren't recorded in the trade directories. It's definitely Sheffield make, though. The flower-shaped pin collars are a dead give away.

Technically, 'Faux Frameback' is a modern designation. The style of grind long predates the popularity of the frameback (though not the existence -- Ebenezer Rhodes made the first documented model in the early 1820's) and was called a Rattler then.