18thC Irish Silver Marks

Hi
I am a newbie to this site so hello to everyone.
I have a pair of small trays with what I believe are mid 18thC Irish Hallmarks. They measure 165mm across and weigh 8oz each.
There is no date mark, but have read this is quite common for the middle part of the 18thC. The makers initials are WT. The only maker I can find for these are William Teulon of Cork. He was registered in the 1790s. The Hibernia mark is in an oval which finished before he was registered looking at the date table.
Did they still omit the date mark in this period please??
Can anyone enlighten me with some more info please. Many thanks.
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I believe that this is probably the mark of William Townsend. According to Douglas Bennett (Collecting Irish Silver 1637-1900) his working dates were 1726-1775 so this style of hallmark ties in well with those dates. The Hibernia mark was introduced in 1731 and it and the harp mark continued pretty well unchanged up to and beyond 1775. No doubt there are subtle differences which an expert might be able to use to tie down the date but I’m afraid they escape me. Neither can I comment on the prevalence of missing date marks.

Many thanks for your swift response. I will look up William Townsend.