Superb condition and quite a rare miner's lamp 

Markings inside on the burner part Naylor Wigan Pattent 44421 I52I and three dots

Marking on the body Naylor Wigan Marsaut 45103  Bifold Burner

In excellent condition including mesh filter and glass with marking (Bulldog head?) JHN

The top black lacquer on gold 

Next to the burner 2 missing screws?

Untested

Size 24cm without hook bottom 8.5cm

Weight 1379g