Quick explanation here...
The rear struts you have are Gas Charged with Air assist... So it possible for the gas portion of the strut to fail and still have the air portion work fine... And in other cases its possible for the air portion to fail and have the gas portion be ok.. In your case the air portion is almost dead..
You can put the rear struts on the car but you will need to give yourself alignment marks so you can get the alignment as close as possible... After that you will have to have the alignment reset..
If you intend to replace the struts I would recommend Monroe Matic Plus struts or Monroe Sensatrack struts.... Either of these would be great... If you are going to do the struts you might just as well do them all the way around and do the alignment once and be done with it..
I am wondering tho, have you ever dealt with front struts?