Forgive me if I was not thorough in my research and this brand has been noted before. I was at a flea market and, regrettably, did not pick this one up, but I did snap a picture of it. I've personally seen a number of razors with the familiar GB and maltese cross, but this is the first I've really seen with a manufacturer name as well (Laycock Brothers, Sheffield).

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I didn't have time to thoroughly investigate, and don't know if maybe this was a trademark that was bought and reused later, or if it was completely unrelated to George Brittain / whatever the older ones were. The Sheffield Indexers have these listings for "Laycock" and "Razor", and the style of razor is certainly consistent with late 1800s:

Laycock, Jno. (~, Razor Mnfr.).
Residing at 23 Netherthorpe Street, in 1871.
Recorded in: Whites Shefffield & District Directory - 1871.

Laycock, Samuel (~, Razorsmith).
Residing at ~ Bramall Lane, in 1871.
Recorded in: Whites Shefffield & District Directory - 1871.

They are not listed as brothers, but they are operating at the same time, so I guess it's conceivable, though the addresses are across town from each other. Anyway, an interesting piece in the GB history. Just wanted to get it out there if it is helpful to anyone or spurs more research. I'd love to hear if anyone has more information on this company.