Is the expression Get shed of or get shut of?

According to the Phrase Finder, “get shut of” meaning get rid of is an obsolete expression:

To get shut of something does seem to be a rather old expression, and more a dialectal than a mainstream one, according to the Oxford English Dictionary, which I quote with all its citations.

From the OED:

" 11. a. To set (a person) free from, relieve of (something troublesome). Obs[olete] exc[ept] in passive (dial. and colloq.) to be, get shut of, (dial.) shut on, to shut one's hands of: to be rid of, free from; also ellipt[ical].

?a1500 Chester Pl. II. 31 Though he have healed thee, Shute from us shall he not be. Ibid. 33 To shutte hym of his dangere.

1575-6 Durham Depos. (Surtees) 312 This examinate promised..that he

wold marye the said Grace..so that he might be shutt of the promiseshe hadd maid to one Marian Raic.

1737 WHISTON Josephus, Antiq. XIV. i. 3 His own life would be in danger, unless he..got shut of Aristobulus. 1827 J. F. COOPER Prairie

1848 MRS. GASKELL Mary Barton I. v. 68 As for a bad man, one's glad enough

1914 D. H. LAWRENCE Widowing of Mrs. Holroyd III. 84 Who dost think wor

1976 S. BARSTOW Right True End I. iv. 65 'I haven't got her.' 'You're well shut, from all I hear.'"