Ubercart Mall Vendors

Does anyone know of a way to allow multiple vendors(roles) create their own specific products and sell them to other users?

I need the ability to allow individual companies(in a mall) to login, create their own products, and then sell (as a point of sale system) those products (only theirs) to other users(either registered or anyonymous).

I created a "vendor" role. Allowed them to creat products, and also given them admin permission to creat orders. So far so good. At the order process, a new customer can be added or they can choose an existing customer. Still good so far.

Here are a few challenges I've ran into.

I haven't been able to force them access to only sell their own products when checking someone out. Since a vendor role has access to create or edit orders, they also have access to all products. I need to limit thier access to only their specific products.

I've tried the marketplace module in ubercart but it didn't solve this. I don't know of any other way to allow one user to sell products to another user either.

I would appreciate any ideas or suggestions.

A recap - I want to be able to allow multiple vendors in a mall to sell their own individual products to all the users in the system.