After looking on their website one can see that the die crack, early though it is, has succumbed to the usual contemporary tooling.
The leaves on the wreath and high points on hair are flattened. The reverse shows wear concomitant with that exhibited on obverse, lion’s breast and ribs in escutcheon, jewels in crown, Irish harp etc. Peripheral residual lustre is present so I’d give it a generous Sheldon of EF45, so in that context it is “extremely fine” though only equating to VF in ‘real money’.
I’ve seen worse examples go for more than £6,750* and better examples go for less.
* here’s an example of someone blindly trusting the grade on the slab (MS63😂) and shelling out £11,500 for an example which I’d have to be put in a headlock to offer £4,000 for.
https://coins.ha.com/itm/great-britain/world-coins/great-britain-cromwell-crown-1658-7-ms63-ngc-/a/3056-30267.s?ic4=OtherResults-SampleItem-Thumbnail-022817&tab=ArchiveSearchResults-012417