Even in a “world” without currency, there is ALWAYS a trade currency, isn’t there.
Gotta figure a lot of wealthy people would buy their way on to a project like that and likely be a big source of funding. Few would be willing to give up their social status and I’m guessing social mobility would be nearly impossible.
Its a small sealed society and kind of has to be that way. The wealthy would make up the top level administration. The ship’s crew would be close to the top with the technicians making up the bulk of the middle class. The guys at the bottom would be those who do the production, everyday maintenance, cleaning etc.
I can pretty much guarantee there would be no welfare.