design a retractable ballpoint pen - open to bidding

design a retractable ballpoint pen based on the design (blue pen) pictured below - to accept Parker pen refills - modify the advance mechanism from a top push to side advance through a sliding button on the left side, similar to the pictures of the white pen - extend the top of the pen by so that the body is ~13.5cm long in total - modify the clip to be nearer the top of the pen so that it is a better fit, easier to put in and take from, for a shirt pocket (a smiler concept as the clip of the white pen) - avoid any narrowing or tapering of the pen as it approaches the writing end - prefer if the pen does not come in two halves (i.e. screw apart in the middle) happy with a longitudinal split where I have to insert pieces of the mechanism to advance / retract the refill then glue the two halves together then screw on / off piece at the bottom (similar to the silver part of the blue pen) to insert and extract refill / spring