I used to have Michael Hanratty's phone number and we spoke on some occasions and this was a point I brought up with him.
This was his reply: "When I went to see Jimmy in prison I mentioned about hiding stuff under the back seat of the bus." Jimmy said: "Look Mick I know I am not the brightest in the world but do you or anyone else seriously think I would shoot and kill someone and then leave the murder weapon on a public service vehicle where it was bound to found. I would have chucked it in the river somewhere. Yes I admit I did used to hide unwanted or worthless jewellery under the back seat but that is all."
I recall that one of the pro-Hanratty arguments was that he would not have used the word "institutions" as used by the gunman in the car according to Valerie Storie, yet here we have a well authenticated instance of Jim using the phrase "a public service vehicle" rather than what most folk would say, namely "a bus".
Maybe Jim was not as linguistically backward as some would have us believe.
I would think that as he spent a lot of his earlier life in such places, the word 'institution' would be one that JH would have known only too well.
Woffinden (P 91) illustrates what he describes as JH's basic inarticulacy when he describes France as 'someone who learned me previous occasions when I was younger'. I don't think this brief passage is all that inarticulate, to be honest, certainly no worse that what I hear kids shouting at each other these days. I don't recall anyone in any of the books being referenced as saying that they couldn't understand him or what he was talking about. He may well have stumbled over his words when under the severe and unimaginable pressure of the court-room, but I don't get the basic impression that in everyday life his diction and use of English was anything out of the ordinary. I may be wrong, of course.....as a Midlander I have always had trouble in fully understanding the modern-day London accent, something which the BBC and southern English people in general may well find difficult to understand in turn.
We are suffering from a plethora of surmise, conjecture and hypothesis. - Sherlock Holmes, The Adventure Of Silver Blaze