I wasn't sure what the leaf size was on kumquats since my seedling hasn't produced its first set of true leaves yet.
I've managed to get over 50% leaf reduction on my citrus though. Your leaf size doesn't look bad in the pictures.
Brussels bonsai nursery does sell calamondin orange for bonsai. Not sure if its a kumuat or a hybrid of it, but heres a link
http://www.brusselsbonsai.com/shops...ndinOrange.html
Looks great fruiting.... thats the drawback of citrus by seed though... will be about 10 years till mine fruit
