Pre Trek they had 1 1/4" head tubes, a hangar for the cantilever rear brake and press fit bottom bracket bearings necessitating a square taper BB spindle. Yours is definitely a later one.
In the early 90's Klein were horrifically expensive with the Adroit the range topper. When Trek bought them out they did away with signature things like the one piece bar and stem and rigid Strata fork, loaded them with cheaper components and tried knocking them out by the lorry load. But in doing that they destroyed what Klein were all about - low volume, beautifully made, exquisitely painted and uncompromising designs. They instantly lost everything that made them desirable bar a few fancy paint schemes and Trek let the brand fade away.
Here's one of the last pre Trek Adroit's for comparison -
http://www.retrobike.co.uk/forum/vie...p?f=2&t=394732