Green’s Dictionary of Slang

shab-rag adj.

[dial. shab-rag, a mean beggarly person, a ragamuffin]

shabby, damaged, worn; also in fig. use.

[UK]Bridges Burlesque Homer (3rd edn) 434: None of your Birmingham affairs, / Nor any such-like shabrag wares.
[UK]Bridges Burlesque Homer (4th edn) II 254: [as cit. 1772].
[UK]Huddersfield Chron. (Yorks) 30 Aug. 6/4: We can have shab-rag mayors, and shab-rag aldermen.
[UK]Yorks. Gaz. 8 Aug. 8/2: That money which is wasted [...] amongst shab-rag noblemen and soiled noblewomen.