Mercia, Burgred Penny, Ciallaf, inverted F in name, no lips to King

Burgred, King of Mercia (852-874), silver Penny, Phase IIa, Moneyer Ciallaf, diademed bust right to bottom of coin, linear inner circle and legend around, toothed border around rim both sides, legend commences lower left, BVRGRED REX- rev. three line inscription across lunettes above and below, +CIALLA / F MON / ETA, the F inverted, weight 1.28g (Mackay H1.7 O3/E3; N.423; S.942E). Toned, small rim chips, some hairline scratches on neck, otherwise good very fine.