The serial number is actually 78 C 0788 which means that is it the 780,788th rifle built at the Savage (C = Chicopee) factory.
If a rifle is marked with 'England' that is an IMPORT mark from the receiving country - it is NOT an EXPORT mark, we did not mark for export.
The NP mark means it has been proof tested in the UK for sale to the UK civilian gun trade, so, it was sold to a UK civilian dealer and then either to a UK civilian, or to a US importer. The NP is NOT an export mark.
Hope that is a help for some of the markings.