Is there anywhere I can see the scripts of the Qgis core plugins.
Source code for QGIS is on Github: https://github.com/qgis/QGIS/
The plugins are at https://github.com/qgis/QGIS/tree/master/src/plugins
If you need to get source for a particular version of QGIS, its probably easiest to download the relevant tarball, although you could select from a branch. For example, for 2.6 it would be https://github.com/qgis/QGIS/tree/release-2_6/src/plugins
Note the licensing conditions on the source code in the header.
Just look on the github page at the source code https://github.com/qgis/QGIS/tree/master/python/plugins