Obverse:

ELIZAB D G ANG FR ET HIB REGI. Crowned bust 6C l. with rose behind.

Reverse:

POSVI DEV ADIVTOREM MEV. Square topped shield over long cross fourchee dividing the legend. Date above with a large 99 struck over 98.

About fine, extremely rare date and mintmark, the overdate even more so. 

Ex W. Wilkinson Collection - Exchanged with Comber 20 Oct 1997

Ex C. Comber Collection