The SU-33 is built by Knaapo (a Russian company) Sukhoi is (a Russian company), both headquarters of knaapo and Sukhoi are located in Russia. Purchasing an aircraft from Ukraine doesn't make it Ukranian. Bottom line, Sukhoi is a Russian company.
Don't have the ability to produce?
Sukhoi has produced everything from the SU-30MKK to the SU-35 to the PAK-FA and of course the SU-33, the only thing Sukhoi would need to do is restart the production line which would not be a problem finacially since Sukhoi is one of the most profatable aircraft manufatures in the world.
We asked for money did we? More like Russia declined China's offer.
Russian-Chinese Su-33 fighter deal collapses - paper | Russia | RIA Novosti