Green’s Dictionary of Slang

(orig. N.Z.) copper coins, small change (note cite 1938).

1918		Aussie (France) 4 Apr. 10/1: Then there was the other shrap, w’ich was those little, dirty, patched-up pieces of paper we useter use fer money, worth anythink from tuppence-app’ny up.
1919		A. Baer Two and Three 24 Jan. [synd. col.] Toss some Woolworth shrapnel [...] Jitneys and dimes.
1938		Press (Canterbury) 2 Apr. 18: ‘[S]hrapnel’ was the name given to tattered French paper currency.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 11: The freight to Balmain had not left him with much shrapnel out of a deep-sea-diver.
1988		McGill Dict. of Kiwi Sl. 102/2: shrapnel small change; originally used by WWI soldiers of French small currency notes that were worn full of holes as if hit by shrapnel.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 59: Big Oscar emptied out his change tin [...] where he had the habit of tossing all his shrapnel and the odd ten-bob note.
2000		J.J. Connolly Layer Cake 96: I give my man about twenty-seven pence in shrapnel.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Shrapnel (n): loose change.
2007		D. Szalay London and the South East 64: Paul jangles the heavy mass of shrapnel in his pocket.
2012		R. Milward Kimberly’s Capital Punishment (2023) 384: I’m not even sure I want to go abroad [...] if it leaves me with just a tiny pocketful of shrapnel.
2019		C. Hammer Silver [ebook] Just as he’s inserting the last of the shrapnel [into a charity tin] [etc].
2023		R. Milward Man-Eating Typewriter 472: I parkered the fungus all the shrapnel I had left jangling in my inside posh.