As a nine or ten year old in nw London I loved Desmond Dekker's Israelites but I reckon my version of the lyrics when singing along was 90% mondegreens. Even now, when I hear it, a lyric jumps out for a "oh that's what he sang!" moment. The advert on the TV (for Maxell tapes?) was with the mondegreen lyrics written on it culminating in (the already mentioned above but it's too good to not repeat) my ears are alight!!!!!

Get up in the morning searching for breksa (breakfast?).

Also, a few years later I could have sworn The Jam's Eton Rifles actually had the chorus "eating trifles".

And what are the proper words that still sound like "Bless my cotton socks I'm in the nude"?