Nice job! Latch used here is called toggle clamp often used as workholding tool. I would suggest to go with quick release toggle latch, e.g. something from these: https://www.ojopsweden.com/product-category/ojop-toggle-latches/Thanks Mike.
Spindles are from http://www.comp4x4.com and latch is from http://www.goodhanduk.co.uk/