I have a bunch of U2 boots and yet this recording is not among them. That’s why we have YouTube.
This recording was made at the Dandelion Market in on May 12, 1979, two days after Bono’s 19th birthday. Admission to the show was 50 pence (about 70 cents). The audio was recorded by Peter McCluskey, the guitarist in The Stougers, who were the night’s supporting act.
(Thanks to Larry for the link.)