I have the Comer with a slip clutch. It list no part numbers for the tube. The Eorocardan # 5&6 are the parts i need.
You are correct the shaft half parts are not broken out by Landpride.
I will attach a Comer document that may help you determine which series and style of pto shaft you have.
Unfortunately this document is in a number of languages which make it tougher to find what you need.
The pto shafts are rated in series. 10 to 80 I think. My 75 hp tractor uses the 50 series so I would expect your tiller is a 50 series or smaller.
Page 4 & 5 show shaft cross sections and dimensions which should make measuring yours compared to the profiles easy.
Companies like Agristore should be able to provide you with the shaft halves. If you can tell them the Comer series it makes things easier and they may recognize the Landpride number 826-505C . The "50" may be denoting Comer 50 series.
Don't give up. You have a quality pto shaft. You will be able to move anywhere in the world and find parts for it.
Dave