Hello Mike,
You may have this information already, but browsing through The Times...
Monday, Dec 08, 1879; pg. 13; Issue 29745; col A
Advertisement in the classified section mentions a "Robert Plant, Esq,. Cheadle-park" as one of the patrons of the Householder's Pure Milk Supply Association (Limited). Item was repeated on Thursday, January 15 1880.
Saturday, Jan 14, 1888; pg. 17; Issue 32282; col A
Advertisement in the classified section mentions one "Robert Plant, Esq., Chairman of Majors Barn Colliery Company Limited, Cheadle, Staffordshire" as one of the directors of the Cheadle Railway Mineral and Land Company (Limited). Item was repeated three times during the following week.
Dave