gas hood?

[OldBraggs]

while unpacking some mouldy boxes and bags we found this. It seems to have a white powdery substance, which may be mould? Didn't fancing breathing near it, but took some images and packed it away again and scrubbed my hands! It had 2 small wooden boards packed either side of the viewing panel.
Steve

[kradman]

Yes looks to be a gas hood , nice find

[Jerry B]

Looks to be correct, probably worth a few quid these days, image from wikipedia