China-Duchess China from England

This cup and saucer is by Duchess China as shown on the bottom of the saucer. Oddly each piece appears to be what I would describe as a "second"..there are little paint brush strokes of the gold..drops of black...etc. It is very thin china ...and I was told by the lady that I received it from that it was about 100 years old. I have not been able to identify the pattern. I just noticed on the bottom of one of the saucers there are 4 numbers painted on the bottom..very small in a mauve color..2351 and a little triangle