Richard Waller gets several mentions in the Leeds Mercury in the 1870s and 80s, not sure which of these you have seen, but just in case:-
1870 - painted Charles McGaret for display in Town Hall, Larne, NI
1877 - painted Mr Joseph Holdsworth
1878 - painted Col Forter CB for Henry F Burmester of Leominster, article also states that the Town Hall contains several portraits by him of successive mayors, and that in his gallery there are pictures of Lord Cairns, Garibaldi, Phelps & Ben Webster, also a painting entitled "Mars welcoming Venus"
1882 - the portrait of the member of Leominster was Thomas Blake
1882 - exhibited portraits of Thomas Dawson and Miss Pierson at the Leeds Art Exhibition
1882 - Bond & Barwick were the solicitors for his estate
1882 - Hepper & Sons were the auctioneers for the sale of the Tools, Plant & Patents at the Moor Foundry, Elland Rd, Holbeck from the his estate
He appears to have moved his studios from Commercial St, Leeds to Tower Buildings on Woodhouse Lane, and he advertised around 1880 for students
I believe most of the Town Hall paintings were moved to the new Leeds Civic Hall in the 1930s, the Mayors department there has a list of all the portraits and the artists, and were very helpful when I spoke to them last year.
The portrait of the bearded man which I hope is William Kettlewell is about 36"x28", so may not be the self-portrait which was catalogued, and which is significantly larger.
I hope some of this is useful. Paul