This is a combination of contributions Individual Product Shipping Methods (http://addons.oscommerce.com/info/4674) and Individual Product Payment Methods (http://addons.oscommerce.com/info/4551) in a single file.
This allows you to choose which shipping method and payment method of each product regardless of all that we have. Are all enabled by default, you just have to dial those who need it in individual cases, we will not send a second-hand vehicle by mail but if its spare parts for instance.
In case of conflict prevails shipping method on the payment method.
Adapted for 2.3.4
Also corrected errors mysql that did not occur in previous versions.