Green’s Dictionary of Slang

(Aus.) £1; often in pl.

1936		Sydney Sportsman (Surry Hills, NSW) 15 Aug. 1/5: If you’ve still got a fiddley or two left, you'll recoup your recent losses by following Lasting.
1942		Morwell Advertiser (Vic.) 2 July 7/2: [headline] Fined Extra Fiddley For Non Appearance [...] As Farrell failed to appear the Bench tacked an extra 20/- on to the usual fine of 40/-.
1951		(con. 1941) E. Lambert Twenty Thousand Thieves 154: Gentlemen, I require two fiddleys in the old comic cuts.
1968		D. O’Grady A Bottle of Sandwiches 6: We had to fork over eight hundred fiddly-bloody-dids for her. [Ibid.] 99: I had to shell out around two hundred and fifty fiddleys.
1977		(con. 1941) R. Beilby Gunner 297: One quid. One fiddleydid. One hundred ackers.
1989		R.G. Barrett Boys from Binjiwunyawunya 305: Fivers and tenners, eh. Lady Godivas and bricks we used to call them, Les. A quid was a fiddley did .
2002		Pete’s Aussie Sl. Home Page 🌐 fiddley-did: a quid, one pound sterling (obs.).