[BillDWVA]

Hi,
It looks like your stop switch is intact but that the spring moving part of it has broken and no longer pushing the button back up. The spring contact strip appears to have fallen to one side in your photograph. Remember that the contact closes to stop the motors.
I suggest that you dismantle the switch. If the springy contact has indeed broken you may be able to find some suitable thin strip to make a replacement?
The design of the switch is simple and would have been made by the Ferrograph company themselves.
Hope this helps?
Bill