Green’s Dictionary of Slang

1. to repair and ‘revive’ old clothes for re-sale.

1850		H. Mayhew in Argus (Melbourne) 30 Apr. 4/5: The best black suits are to be ‘clobbered’ up—and those which are more worn in parts are to be cut up and made into new cloth caps or gaiters.
1865		Sydney Morn. Herald 12 July 8/4: Old clothes, before being offered for sale, have to be ‘clobbered’-in other words, patched and sewn-so as to be in a wearable condition.

2. to dress up.

1879		‘Autobiog. of a Thief’ in Macmillan’s Mag. (London) XL 501: I used to clobber myself up and go to the concert-rooms.
1887		W.E. Henley ‘Villon’s Good-Night’ in Farmer Musa Pedestris (1896) 174: You judes that clobber for the stramm, / You ponces good at talking tall.
1893		P.H. Emerson Signor Lippo 55: One day he walked straight into this kitchen clobbered in a pair of rounds, tight to his legs, [...] and a long sleeve cadi on his napper.
1901		Sydney Sportsman (Surry Hills, NSW) 1 May 1/6: Clobbered up in style and fashion / Loud as any German band.
1901		W.S. Walker In the Blood 47: I ain’t allays too well clobbered. This is my Sunday-go-to-meetin’s I’ve got on.
1906		E. Pugh Spoilers 4: Bin ’angin’ about the Scrubbs an’ then ’ere for nigh on three weeks, I ’ave, clobbered up like this.
1909		J. Ware Passing Eng. of the Victorian Era 94/1: ‘Thank God,’ she observed, ‘I’ve got a costume play at last. I shall klobber in Crimson and gold for the first act, blue and amber for the second, and pure white and silver for my death in the third. I shall make a great success.’ [Ibid.] 163/2: So I klobbered myself up as well as circs would permit.