This is an Orange Free State stamp from 1900.  It is SG 57a, the 1d on 4d Ultramarine Type A Double Overprint with a wide base to the 1 in 1d.  It is in fine to very fine Used Condition with a cancel on it, that is well clear of the overprints.  This is valued at L120 in the SG Catalog.  This is a very rare and lovely little stamp.

This lot is over $100 USD so I will ship it using priority mail in the states or registered mail overseas, to ensure that it reaches you in a safe and timely manner.