Green’s Dictionary of Slang

conoblin rig n.

[rig n.2 (1)]

(UK Und.) cutting the strings that attached large pieces of coal to the doorways of coal sheds, i.e. stealing coal.

[UK]H.T. Potter New Dict. Cant (1795).
[UK]G. Andrewes Dict. Sl. and Cant.
[UK]Lex. Balatronicum.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue.
[UK]G. Kent Modern Flash Dict.
[UK]Flash Dict. in Sinks of London Laid Open.