"Soldiers half a crown, Sailors if they're willing
Big fat men, two pounds ten
Little boys a shilling.'

So the song went when I was in bellbottoms.

From Reflections on Blue Water: Journeys in the Gulf of Naples and in the Aeolian Islands, 2012 [originally published 1999], by Alan Ross

"Alan Ross" (1922-2001) was a poet, writer, journalist, editor
and publisher. In fact, he was a man of letters par excellence.
Born in India, educated in England, he joined the Royal Navy in
the Second World War and endured the Arctic convoys to Russia.

See text in google books:

https://www.google.com/books/edition/Reflections_on_Blue_Water/D9iVbFxUDn4C?hl=en&gbpv=1&dq=%22soldiers+half+a+crown%22&pg=PT128&printsec=frontcover