The OED defines a nobbler as a small glass or container for liquor (no amount specified). In print, this usage has been found back to 1852.
Also defined as a groom, or nobbler of horses, usage found back to 1854. Also a stick used to knock someone in the head (1880s). Also a stick used to kill fish- originally nobby.
To steal (used by Thackeray)- back to the 1850s. To obtain by dishonest means- 1850s.
To swindle, to bribe to get hold of, to seize---and on and on.

In the 18th century (or before), a nob was slang for the head. A nob thatcher was a wig maker, also called a nobbler (In various dictionaries of cant and slang, but not in the OED).

In other words, take your pick of meanings or invent your own.