"Colin Chaplin" wrote:
It's definetly double glazed - the outside pane has a hole in it whilst
the inside pane is intact, and from what I can see theres a metal frame
around the two panes, so it's just like a mini double-glazed window pane.

In that case a local double glazing repair firm should be able to make a
replacement sealed unit to order of the correct length, width and depth.
Take the damaged unit with you for sizing and matching of the glass if
patterned or coloured.