Green’s Dictionary of Slang

(gay) one pound.

2010		W. Ings ‘Trolling the Beat to Working the Soob’ in Int’l Jrnl Lexicog. 23:1 64: [A] shilling was a beyonek, a half crown, a tosheroon, and a pound a ponte.
2019		P. Baker Fabulosa 296/2: ponte, poona a pound (money).