Estate items that have been stored away for over 12 years.

The glass and backing is not present on one, as well as 2 of the screws which have tabs to hold the backing are missing.  They had become lost in packing up the contents of a house and we have never come across them after unpacking everything.  If you have a spare or unwanted other frame it is likely a similar sized back that can be swapped in.  Having only 2 hold-down screws is probably sufficient.