I am not sure if there is a reliable online source for the information you need. The usual master reference is the Spink annual book - equivalent to the US
Red Book, but that is hardcopy only.
This book:
https://www.amazon.com/Collectors-C...books&sr=1-1is available on Kindle, if that suits?
Yes, there are 3 main varieties for the 1887 sixpence:
The Young Head variety - same style as since 1839 and last year of issue, a bit scarcer than the other two.
The "Withdrawn" variety - Jubilee head and shield reverse, withdrawn because it was too similar to the half sovereign and the criminal fraternity quickly started plating them and passing them off. Actually the most common as people kept them as keepsakes.
The new variety - Jubilee head and reverting to the Sixpence words reverse, in production until 1893. Valued the same as the withdrawn type though slightly less common I think. This is the one you have.
Yours is in such poor condition that it would go into the scrap metal pile here in the UK, but you might get a few dollars for it in the US.