Design and manufacture of a simple circuit - repost

(This project has been reposted because attachments were not all shown in the original and there appears to be no way to add them once the job is posted.) In order to test a piece of equipment we support we are looking to develop 5 test boxes which will plug into the supported equipment and act as go/no-go testers of same equipment. The new test box consists of an enclosure with three connectors (only): 1. HDB-15B male connector (D) 2. HDB-15B male connector (H) 3. 3.5mm 3-pole female audio connector A block diagram is shown in the attachment. The text box contains four identical passive networks (see attachment) for two sets left and right channels. The passive network for each channel consists of 3 capacitors and 3 resistors. A LTC2990 (or similar) measures four voltages and provides access to these via I2C. WHAT WE PROVIDE: 1. the above functional description 2. answers to your questions 3. payment for your labour as well as manufacturing costs which you incorporate into your bid WHAT YOU PROVIDE: 1. schematic, layout and manufacturing files (we have no preference for the cad tool you use) 2. proposal for enclosure 3. documentation showing that the box you have designed works. We will not provide an I2C master, you'll need to have access to one yourself to be able to demonstrate that the voltage measurement is working correctly. 4. five fully built, fully enclosed units. We can provide you with a FedEx account number so no need to include shipment costs to us within your bid 5. you look after the component procurement, manufacturing and assembly of the boxes 6. a bid that includes the material, build and assembly costs. If you need to bid with some risk in these costs please specify the degree of uncertainty in your bid. The expectation is that given the simple nature of this project we should be able to get fairly accurate estimates at the time the bids are made.