(K)Z1100 A1 rear shocks.

Hello! My first topic. I have a 1981 Z1100 A1 that I have owned since 1992.
In the late 90's I put on some Koni shocks to replace the original air shocks.
A few years ago one of the Koni shocks developed a small oil leak, and now I would like to refit the original air shocks.
Does any of you forum members know where I can get the original shocks rebuilt?
Like the way they look, and would like to use them!
Thanks!