Possible probable definite, but let it stand - red herring time .... Could the nephew have been Claude Hooper Bater, born 12 May 1862 in Barnstaple, Devon, parents Alfred Bater and Mary Ann Hooper? He graduated MA (not MB) from the university of Glasgow in 1891 and is in the 1891 census in Partick. Though I can't see any obvious - or even possible - connection. He died in Kent in 1934 and probate was granted to Emily Rose Bater (b 1900), wife of Ernest Perkins Powell. Emily was the daughter of William Alfred Bater, born in Barnstaple in 1855, Claude's elder brother.
The 1895 Valuation Roll lists 4 occupiers at 6 Carrick Street - Isabella Prophet, Agnes Pirie, Murdoch Matheson and Thomas Wilson, so if Claude Bater was still there in 1895, he must have been a lodger or boarder.