This is an Orange Free State 1881 SG 25, the 1d on 5 Shilling Green.  It has a larger 1 in 1d with a sloping serif at the top.  The bar on the foot is also thinner.  It is in Mint Original Gum with Hinge Remaining and fine to very fine condition.  This is valued at CV L550 in the SG Catalog.  A lovely find for an Orange Free State Collection.

This item is over $100 USD so I will be shipping it with priority mail in the states and registered mail overseas.  This is to ensure that it reaches you in a safe and timely manner.