I am unable to help you because I don't understand your size designation.
The first number should designate the screw size. The second number is the thread pitch.
1.25 is a standard metric pitch but on larger threads.
What does the .050 designate? Is it measured in MM?
I don't think your giving the needed info. It seems your measuring thickness & length. If you have a jeweler or an optician nearby who does repair they will probably be happy to measure a screw for you.
Once you know that, sourcing a replacement will be much easier.