Klein headset

[johnnyt]

I have an old Klein Attitude with mission control bars and fixed headset and rigid fork. I would like to install a front shock and new bars and stem, but have no idea how with this headset. Below is a picture. Does anyone know how to convert this to either threaded or preferably threadless? What size is it? My guess is 1" because it is about 10 years old.
Thanks! - JT

[joe]

If you know what year it was made this manual has a good deal of information on pre-1997 Klein bikes.

(it's a PDF file, convenient for downloading and saving if you have one of these bikes):

http://www.kleinjapan.com/tech_guide/pre97_klein_tech_manual.pdf