That's it, RJ.
Barmaids blush: beer and raspberry or port and lemonade as well as rum and raspberry. The oldest reference I could find was from Tasmania in the late 19th century, and the meaning of the term was also considered by the Western Australian Full Court in 1912, counsel suggested it might refer to a barmaids intoxicating smile! You might like this excerpt from Bill Bowyang in the Townsville Daily Bulletin 22 August 1938:
Just then a townle bloke, hatless, wearln a black sports shirt with sleeves chopped on at the elbow, sportln a wristlet watch, an wearln a pair of grey flannel strides with hips big enough for a publicans wife, taperin in under the knees, swellin out like a balloon an just showin the tips of his shoes, bowls over to me an says. Have a drink, Bushie. Ex cusin meself for not refusin, I calls for a double rum an sinks it neat, while the toff is drinkln a ladles waist of barmaids blush. Knowin In me heart its Have another, and not Come an have a drink, that keeps me on me hocks in the ashes, I says, Give it a name. He has his beer and raspberry again to make bis breath smell pretty, an I sticks to me giggle soup.
Bill Bowyang was the pen name of journalist Alexander Vindex Vennard (1884-1947), who had an interesting life.