Marx did NOT mention any such thing as "ownership of production and distribution by the Party" anywhere in his writings. In fact, the goddamned Communist Manifesto its own self said the following:
The Communists do not form a separate party opposed to the other working-class parties.
They have no interests separate and apart from those of the proletariat as a whole.
Lenin conceived the need for a tightly-organised, centralised, quasi-clandestine Marxist party in the conditions of Tsarist autocratic repression. This party ended up assuming the dictatorship of Russia/the USSR in the aftermath of the traumatic Civil War, total economic collapse and the consequent collapse of the working-class democracy of October 1917. It is the fault of idiots (and to some degree even some brilliant people like Trotsky) that some people think now that that's the only way Marxists should organise themselves, ever.
Whether Marxists should have their own party, and how it should be organised, depend on the concrete conditions in which they face themselves. To say that we should always organise as "toy Bolsheviks" is like saying that all Thelemites must get together a hierarchically structured Order like the OTO or the A.A. Mistaking the map for the territory in a big way.
Also, the rigid "stages theory" ascribed to Marx is Stalinist orthodoxy, rather than living Marxism. Check out the idea of the "Asiatic mode of production" to understand that the theory as presented is a caricature of Marx's rich, complex and ever-evolving though. Stages theories don't work.