To avoid any potential problems merging runtimes from vastly different versions, I would use the P7 as an external runtime.  The available download folder within the Poser folder could suffice, but many experienced users bypass that for more customly specialized and organized folders.  The only drawback would be utilizing any python script originially installed into your P7.  As described above, copy your PP2010 python folder to the P7 runtime, then copy it back to PP2010.  But remember to backup those files first just in case your app Python Script misbehaves.