That's the thing, I'd imagine that COMAC will be funding most of the project since the Russian advantage is expertise while the Chinese advantage is money.
China is not funding more than 50% of the entire project, the funding has being divided equally in 50% for Russia and 50% China.
it means 50% for each side, the construction rights probably is 50% of the aircraft is build by Russia and 50% for China, this means the profits very likely are divided in the same way.
there are 2 engines options, the PD-35 for airliners that want a Russian engine and american or British engines for those airliners wanting a foreign engine.
Only China will have the final assembly line, Russia will have only manufacture and design centers.
China is not investing more, the only reason it was decided the final assembly will be in China is because China has a Market 4 times bigger for commercial aircraft than the CIS countries, China has being predicted will buy around 6000 aircraft in the next 20 years, the CIS countries around 1500, thus the decision of having the assembly line in China was because China is supposedly to need around 600 aircraft in the B-787 class, while the CIS might not need more than 150-200 aircraft
But if i am not wrong even PD-35 might have Chinese components