According to my Seaby "Coins of England" ,"Low Tide " pennies were issued during the reign of Victoria (in 1895) and Edward VII (in 1902) but not in 1921 (George V). "Low Tide" versions of pennies that were issued are generally valued higher than the normal "High Tide" pattern. Current valuation for say, a "Low Tide" Edward VII 1902 is in the region of £55 if in UNC condition (uncirculated).

A bit more info on George V pennies, coins struck at the Heaton and Kings Norton mints have H or KN in exurge to the left of the date. 1912H (£125), 1918H (£275) 1918KN (£1250), 1919H (£280), 1919KN (£1500). All these values are for coins in UNC condition, the price depreciates rapidly for lower condition examples but they still command higher prices than "ordinary" pennies of the same dates. There were modifications made to the coinage during the reign of George V.  In 1926 the obverse had a modified effigy of the monarch, in 1928 it was modified again with a "small head" effigy. The Heaton mint (H) was also used during the reign of Victoria the "H" is present on a number of pennies in 1874,75,76,81 and 82, the H is shown below the date and can be difficult to spot due to wear on the coins.

How was Norfolk Cally? we had a smashing Time up in Whitby.