Harry Champion was a music hall singer of (I believe) ~1900-1920 in East London. His songs often reflect the time period and location that he lived in. In his song Samuel Duff, the lyrics of the first verse are as follows:
My father always used to say you ought to wear a shine
To show the people what you're paid and what's your proper line
So upon me face I wear this little bit of fur
Because I am a sideboard manufacturer
When they see me sideboards when I'm walking out
Dogs begin to bark and people all begin to shout
In this context, what does "shine" mean?