Green’s Dictionary of Slang

Walter Scott n.

[rhy. sl.; ult. novelist Sir Walter Scott (1771–1832)]

a pot (of beer).

[UK]J. Franklyn Cockney 293: In the presence of an ‘observer’ [...] the request will be for a Walter Scott (pot) of pig’s ear (beer).
[US]Wentworth & Flexner DAS.