The stop is a stainless pin. If you look at the inner tube on the end that goes inside you should see a hole about 3/16". You can use a clevis a little longer, cut off the head and round the ends a bit. It should just fit in the outer tube. Also the pin floats and is not glued in any way.

Two ways to do the next step. At the yoke end there is a collar with two roll pins. Remove the pins, slide the collar off, take the handle off the outer tube, slide the inner tube all the way in. If the pin is long enough it should stop. Replace collar and handle. Those roll pins tend to corrode to the aluminum and need to be drilled out which can be difficult. So the other way is to simply shove the pin end of the inner tube through the locking collar at the end of the outer tube.