This coin clearly has pellet end ornaments to the crown, X type 2 and round eyes - suggesting sub-class 5a2. However when we look at the two instances of the letter R, the first one is clearly the wedge-shaped R1 whilst the second is either R1 or possibly R2. R style 1 does occur on 5b2, 5c2 and 5c3. The round eyes rule out the 5c pennies, and the style of the letter X (X2) leans against all three. The coin appears to perhaps be transitional between 5a2 and 5b2. The reverse of the coin shows clear examples of R2 supporting the 5a2 interpretation - and this is probably C/T type L549. The wedge-shaped R though may confuse many collectors.
Example - a class 5 coin of Ricard of London:
Round eyes and X2
Round eyes and X4
Almond-shaped eyes and X4
Round Eyes & Normal Central Fleur, X4
Almond-shaped eyes & Normal Central Fleur, X4
Almond-shaped eyes & Disjointed Central Fleur, X4
All have relatively thick crown bands.
All have X4
R1 wedge & R1 extended wedge (R4) R2 - Ball-footed R3