Complete CubeCart V5 Checkout by Amazon module - "buy button"

This is a repost of a previous project which belonged to someone else & was not undertaken We need a "Checkout by Amazon" module for shopping cart CubeCart V5 -- A checkout button on CC V5.1.5. We have the shopping cart populated with products for sale. mms.reikiranch.net. The module correctly allows customers to login via their Amazon account and choose a payment method to complete payment of the order (all of this functionality has been tested and confirmed as working by Amazon themselves) but there maybe some outstanding issues : 1) The "Checkout by Amazon" button needs to be placed on the cart page using the CubeCart built in hooks so that customers can login to their Amazon account at that point - 2) When the order is fulfilled or cancelled by the store owner, Amazon should be updated accordingly - This should be implemented using the built in hooks within CubeCart V5 so that core code is not changed. A testing scenario where the delivered solution should pass all of the included tests. We would like a copy of all the code work done -- so if we need to reinstall it will be an easy process. A full working dev CubeCart V5 store will be provided by us on our website. You will configure the working version of the Amazon gateway as it currently has been developed. Amazon have recently released some small changes to their code for security purposes and these should be incorporated. Details can be found on Amazon. If you have not worked with Amazon buttons do not apply for this job.