Deferred Revenue and COGS for multiple transactions

Hello,

I have a request from our Accounting Department to do the following”

1. Our Customer requests us to make inventory so we enter an sale order line  for a product (intermediate ingot) we call item A, produce the material, move it customer owned inventory, invoice the customer and defer the COGS and Revenue.
2. In couple of months this same customer will request us to convert this inventory (intermediate ingot) in to a different product item B (pipe, tube, or sheet).  Our Accounting department would like the shipment of this new product Item B to trigger the COGS and the Revenue recognition for item A.