I see lots of pennies of Edward I and II but not many from the reign of Edward III. Therefore, this Edward III penny, which was found by John Lashmar, represents a pleasant change.
On the obverse the legend reads EDWARDVS REX ANGLI, with single annulets as punctuation marks. The legend on the reverse, divided into four sections by a long cross pattee reads CIVI TAS LON DON.
A cross at the start of the legend started to be used during the Anglo-Saxon period. A cross continued to be used well into the late medieval period, when it was eventually replaced by symbols of one kind or another. The penny featured here is a rare and early example of something replacing the usual cross. The coin was struck during series F of the fourth coinage of Edward III and instead of having a cross at the start of the obverse legend it has a crown. In the Standard Catalogue it is listed as number 1587.
The catalogue price for Edward III series F London pennies is the same as class Xc-f of Edward I. However, the former is far scarcer than the latter.
The obverse of John’s find would grade good Fine; the reverse is VF but has been struck off centre. In its present condition I would set the price range at £70 – £80.