I think this is your Robert WALKER.
Ancestry Scotland Census 1891
Brownfield Inchinnan Renfrewshire
WALKER Robert 60y farmer b. Kilbrandon, Argyleshire
WALKER Margaret 58y b. Greenock, Renfrewshire
WALKER James 23y son b. Kilmalcolm, Renfrewshire
WALKER Peter 19y son b. Kilmalcolm, Renfrewshire
WALKER Martha 17y dau b. Kilmalcolm, Renfrewshire
Census 1901
Brownsfield, Inchinnan, Renfrewshire
WALKER Robert 70y farmer b. Easdale, Argyleshire
WALKER James 33y son b. Kilmalcolm, Renfrewshire
WALKER Peter 29y son b. Kilmalcolm, Renfrewshire
RICHMOND Margaret B 35y dau b. Kilmalcolm, Renfrewshire
RICHMOND Margaret 9y g.dau b. Greenock, Renfrewshire
McMEEKIN Isabella 21y servant b. New Monkland, Lanarkshire
Use Scotlandspeople to find Will or Robert WALKER, died 7 Dec 1909.
Britishnewspaperarchives....shows estate worth 6,000 + pounds.
Thank you for finding those two censuses. That certainly seems to be him.
It's interesting how the different censuses give him different birthplaces: Kilbrandon, Kilbarchan (I wonder if this was mistakenly written instead of Kilbrandon), Easdale, Islay, and possibly Oban.