Tom3012 is correct, the holes where used as locators for the original CF hinge pin blocks, that chassis is a bit of a mystery as the prototype chassis's where not anodised. I think that chassis is a pre-production, as the holes where removed for the kit.
Some pic's here
https://site.petitrc.com/setup/assoc....1/C4.1_Intro/
And here
https://site.petitrc.com/setup/assoc...ro/index2.html