I don't know what kind of model you want to use if it is an agent. The model I use is the retail department model of the integration of stores and enterprises, that is, to set up a book company in cooperation with the leaders of the publishing house. The publishing house has a bibliography of library matching and bidding every year. Our company published books according to their bibliographies, and issued a lot of them, but the pressure on goods and delayed payment were more serious, but because of the relationship for many years, it was not a problem.
At the same time, the book company also cooperates with the publishing house to assemble manuscripts, that is, your company plans a number of topics for the publishing house, and they buy them in the form of manuscript fees. Generally, this model does not make much money, nor is it big enough to maintain operations, nor is there any reliable relationship. It is also impossible for a publishing house to solicit contributions.
As for other issues, you can add me to QQ for details.