This addon allows shopowner to add MPN (Manufacturers Part Number) & SKU (Stock Keeping Unit) to each product, in the admin side product adding/editing page.

Product Info PI Layout module is included to display MPN.
MPN and SKU are both added to Product Schema (1.0.8.21 onwards).

This addon changes ZERO core code - simply upload and it is useable. If you wish to display the MPN on the product page, simply turn on the included PI module.

If the price of this addon does not suit your business, contact me anyway. I'm sure we can come up with a good deal that suits each other. Prices are not set in stone.