Beyond the "mini collection" angle here are a few more thoughts and details for Parker specific fans.
Most (I wouldn't presume to say all) of the typical Parkette Deluxe colors (plus a bonus) of the early trim variety fountain pens.
No pencils, and no ring tops - I quit the field in deference to Brian there, but perhaps we could get the turquoise ones along with the pencil I've got for a four way picture some time.
Both sizes in some cases.
Most have the "Plat Plt" nib and USA imprints.
No idea WHAT the heck is going on with that larger gray one with both a lever and room for a button, so I'll just call it a fanciful placeholder for now.