"... if, but only if, you think it right and fair you may take your knowledge of the character of the defendant into account when deciding whether or not his evidence to you was untruthful. It's trite to say, isn't it members of the jury, that a person with bad character may be less likely to tell the truth than a person of impeccably good character? But, of course, it doesn't mean or follow that he, the defendant, is incapable of telling the truth. ... You will also want to bear in mind that the really serious offences of dishonesty, of burglary here, were committed by him a very long time ago when he was a youth, so you must decide to what extent, if at all, his character helps you when judging the truthfulness of his evidence."