Segeltorp

So, I found a set of really cheap KYB gas shocks for the rear struts ($11.99/ea on Amazon!) Only that when I took the struts out and unscrew the big nut at the top of the strut there were gas leaking out and looking in there's just oil and shock componentry - not the shock insert that I had expected.

Upon close examination, the KYB insert seemed to fit ok anyway if I could only get a new nut that could fit over the insert?

Do anyone know about this? Is there a solution or do I need to get hold of new struts that are made for my new inserts??