help identify these gold hallmarks

[katmack7]

Hi,
I have a gold ring and I need to figure out the hallmarks. Any help is greatly appreciated!!!

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[larkfield]

My interpretation, the GW is the sponsors mark, cannot help you on this. The crown and 18 is the carat mark for 18 carat gold, while the shield mark is the the town mark for Chester. The next mark should be the date, not sure but looks to be 1903, whist F is an import mark which I believe was used by Chester on imported items at this time.
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