Hello and welcome Tim,good to see some grass roots modellers here,the delicate art of building small lightweight models is certainly still alive and kicking,if you want to see what can be achieved in building super light scale miniatures take a look at small flying arts,the models in the photo section have to be seen to be believed,light builds is the in thing with modellers shaving down the balsa in kits utilising modern bench sanders to get rid of the led sled heavy wood kits,the balsa is clamped in place and any die cut parts just fall out as the wood is thinned,obviously the slots are then too large but they get round that by packing out with very soft balsa.
I am preparing some tutorials aimed at the small balsa builder for inclusion eventually in that section,best of luck with your balsa models,I love them.