If you want to get at those contacts and pictures, you'll have to install the backup on your iPhone. Once they're on your iPhone, you can transfer them wherever you want. Since the backup is old, your phone will have none of your recent data on it. To preserve the current state of the iPhone, back it up just before restoring it and setting it up with the old backup. After your contacts and pictures have been transferred off your phone, you can now restore the phone again and set it up from the backup you just made before starting this process.