I can't remember exactly, an ex got me his book for Christmas about 15 years ago, I'll try and dig it out. The gist of it was something like an Irish gang(who had "IRA written all over them") were threatening a gang he was involved with and in some meeting with the Irish one of them pulled out a gun and the Guv disarms him, grabs him, threatens to "rip his fackin' face off ya muggy cants if ya don't put those guns daaan"(or something like that) while the rest of the Irish were pointing shooters at him.
Now I'm not doubting that Lenny was a scary bloke but I just find it amusing that members of an organisation that powerful would back off so easily, most likely a bunch of Irish blokes who claimed they were IRA for the fear effect if indeed it happened.