UK Queen Victoria 1887 Sixpence Or Shilling?

I think this is your coin: a 6 Pence http://en.numista.com/catalogue/pieces4722.html

Ooh, ooh, I know the answer to this one.

I made a graphic a long time ago to illustrate the differences.



Based on that graphic, yours is a shilling.

Did you know that design of sixpence was withdrawn because people guilded them and passed them off as Half Sovereigns back in the day? well worth doing for a coin worth 20 times more than a sixpence.
However, one important design change escaped attention: the new sixpence bore a striking resemblance to the half sovereign, as both featuring a crowned shield containing the Royal Arms.
With the same thickness and the same diameter, the only significant difference between the two was the metal in which they were struck, the half sovereign being gold and the sixpence silver. Fraudsters set about gold plating the new Jubilee sixpence, passing them off as gold half sovereigns - worth twenty times as much!
After only a few months of issue, the sixpence was withdrawn from circulation and destroyed. It was replaced by a new design which featured the value "six pence" emblazoned in words on the reverse, which remained in circulation until 1892. '