http://www.gazettes-online.co.uk/ has a couple of hits. In 1888, the firm of P & A Guye (77 Farringdon Road and another address in Geneva), was dissolved by mutual consent of Phillipe Guye, Auguste Guye, Fritz Guye.
There's also something about bankruptcy proceedings for the above in 1879. Phillipe was of St. Jean La Tour, Geneva, and Auguste and Fritz of Macaulay-road, Clapham Common.
Is he the same as the one who died in 1901 in Brentford? Did you try looking for a will? His son by Gertrude (I assume), Edward Fritz Guye, moved to Australia and was in WWI there, later a member of parliament (
http://www.parliament.vic.gov.au/re-member/bioregfull.cfm?mid=1118 )
http://doc.rero.ch/lm.php?url=1000,25,1,18930217_039_08.pdf - some info here! Second page, starts bottom left under the heading 'Hologerie' - it's a wee obituary for Auguste, who died in London, and it mentions his younger brother, Fritz.
Fritz Guye was in Orwell Cottage as of the 1894 and 1896 directories...

In the 1878 directory, August Guye is at 17 The Terrace, Peckham Road, Camberwell. In 1881, Auguste is listed as Auguste George, at Macaulay Rd "Fairview", with various children under the surname George born in Paris and Chiswick (his wife Heloise died in 1923 under the surname Guye).
I suppose there are no good hints on Fritz Guye Browning's marriage certificate? Unless he's mentioned in Fritz's will (or maybe Auguste's?), or you can find a link to one of the addresses that the Guye family used, I think it will be tricky to confirm the link, although it does look very likely.