The parts and service manuals are available to download under the Downloads section of this site. There are two different kickstart shafts, one for the non-oil injection engines and a different one for those with oil injection. The TMX was oil injection, and it appears your bike is also (I see an oil tank in the photo.)
Richard Clark, owner of this forum, has good selection of parts, but some things are out of stock as might be expected after 50 years.