The Geoffrey Cope Collection of British Coins. Newark. 1645-1646.

AR Halfcrown (32x39mm, 14.39 g, 12h), Newark beseiged. In the name of Charles I. Dated 1646. Large crown; C R flanking; XXX (mark of value) below / OBS :/ NEWARK/ 1646. Hird 246 (same dies); Brooker 1222 (same dies); North 2638; SCBC 3140A.
Struck on plate with traces of original gilding.
Well centred. Near EF. Rare thus.