Museumserver

I would like information about some pewter spoons. They have a circular bowl 6 cm in diameter and a straight six-sided handle 11.5 cm long. Impressed in the upper side of the bowl, where the handle joins, are the letters HL and what seems to be a crown.
When were these wonderfully functional spoons made? What do the letters HL stand for. Is there anything to read about them.
Richard Wright