17mm 0.74 g. Billon O: Castle enclosed within two square frames, one solid the other dotted. The mintmark 'B' (BURGOS) appears at the bottom center, overlapping the two frames. O: E+AL o REX CAS o TELL R: Rampant lion enclosed within two square frames, one solid the other dotted. Within the solid frame at upper left is noted a crescent. At lower left an 'X'. These are the marks that do not match. R: B+E o T LE o GIO o NIS o: The 'B' in the inscription appears to be an additional mintmark. The inscription itself also does not match the reverse for C&C 289 as a +(cross) is at the top of the coin instead of a 'T'. The legend for the reverse is however crudely rendered, so take the above as my first guess.