London dialect usage

I found the following sentence in this article and was trying to understand it. I could get the meaning from the context, but I cannot deconstruct the sentence at all.

They introduced pugnacity, backbone and bottle, the latter in the old cockney rhyming slang sense of "bottle and glass" – arse.

I understand that cockney rhyming slang refers to the way London East Enders use multiple phrase words in place of single words, but other than that I am completely at a loss in understanding the sentence.

So,

• What does "bottle and glass" mean in London dialect?
• How does one understand the use of 'arse' in this sentence. (I mean
  grammatically, not the sense in which it was used)?

P.S. If the question seems to be muddled, it is because I could not understand the sentence enough to even ask a coherent question.

Also, I searched google and ngrams for the usage of "bottle and glass", but came a cropper.

Cockney rhyming is a way of substituting one word for another using an intermediate. It is done both for euphemism, and also as a cultural identity, a secret language so to speak.

In the specific case the word bottle is used to mean arse. If you don't know, arse is a British dialect form of ass -- the body part not the animal. So the originator takes the word arse which roughly rhymes with glass, and bottles and glass go together. So the phrase starts out as bottle and glass, and eventually the original rhyme is dropped, so you get just plain "bottle." The rest is implied, if you are part of the in crowd.

Often the word entirely looses the derivation. When I was growing up in Glasgow, the word "bottle" meant courage or bravado. The origins being entirely lost on us. Another example of this would be "lets take a butchers" which means "lets take a look". This was used commonly when I was growing up. The derivation being butcher's hook, which rhymes with look.

In terms of your original question, bottle means courage or bravado. As I say, when I was a kid it was used that way irrespective of Cockney slang. So "pugnacious, backbone, bottle" all live in the same semantic domain of bravado filled, fearless, courageous, belligerence.

Bottle is arse (or ass) from "Bottle and Glass" as the others have pointed out.

The sense of bravery is much newer, and is from the idea of arse=your body, as in "bet your arse", and "put your arse on the line".

This leads to a few other uses.
Having the bottle = being brave enough
Bottling it, losing his bottle= not being brave enough, quitting or giving in.

The expression Bottle and Glass is usually abbreviated to bottle, in line with much Cockney Rhyming Slang, and the quotation gives a clue:

pugnacity, backbone and bottle...

is a set of rough synonyms. But bottle stands for arse.

So botle and glass = arse, like Khyber Pass = arse, and the expression is abbreviated to the first word so it might be used in polite company.