You could still save a lot of weight by replacing the standoffs and their nuts with PVC or another light material. Removing the sockets for the Pic and L293 will save another gram as well SMD components, 3mm LED’s instead 5mm using thinner wires for those sensors and so on.
Oh, try to get thinner PCB’s for more weight saving since this material is quite heavy.
Do you have more photos of the different PCB’s, if so then please let us see them Video…I wonder why nobody else was asking for that…
Well, SMD is tiny, i know But choosing a lighter material for the standoffs and nuts is more easy.
You also can try to drill some material off the motors. The gearbox is brass and you can drill holes in it (not too many and not too big to keep them sturdy) to reduce the weight. I guess you could spare 0.5 to 0.8 gramm if you perform this on both motors.
You can include the video in your page when you copy the link into the video URL field in edit mode.