I've got one by the same makers that I know to have been a working lamp, and it is a little different to yours; I think they've made them for years like yours that folks could buy at the mining museum and places like that and as far as I know they are perfectly functional and will last as long as those certifird to go underground.
Mine, however, is no longer functional as when I went to put it back on it's shelf I dropped it and shattered the glass, so I'm off to try and source a replacement........
Worth talking to Base Camp to see if they have a glass.
I've just bought a spare for mine from them which is a lot cheaper than Protector sell them.