SagePay Form module protocol 3 for custom osCommerce

OsCommerce has a SagePay Forms protocol 3 module in osC version 2.3.4, I need the customizations from an earlier version merging with the attached protocol 3 version and testing with the SagePay simulator using an online test site. (There's likely to be more work to follow too). Important customisations to transfer: i) Test status – change configuration settings to use osC protocol 3 code ii) Function selection – transfer custom code from protocol 2.22 module for n_products_poi iii) Function process_button – include manufacturers_name after the product name in the email message if the manufacturers name exists iv) Function process_button – include products_model after the product name in the email message if the model exists v) Function process_button – check price format vi) Function process_button – switch success and failure urls according to order type, line 185 vii) Function process_button – include the if statements for address field statuses viii) Long $HTTP_ variables to be updated to $_GET, $_POST, $_SERVER, etc.