GE ConstantOn 5mm Bulb Adapter

I have an older pre-lit artificial Christmas tree, made by Santa's Best Craft.  The lights are a GE ConstantOn string.  

The light string uses a weird bulb - it's a 6mm bulb with a weird pinched base.  I can't find the proper bulbs anywhere, but I have a 3d printer, and I can find 5mm round base bulbs easily.

You'll need to get a pack of 2.5v round-base incandescent bulbs. (I used these bulbs)
 

• Printed in Filaments.ca Econofil Dark Green but I bet that just about any filament will work
• .08 layer height (or smaller).  They don't take long to print at finer resolutions
• No supports
• You'll probably want an outer brim for better bed adhesion