Oh, you drive a Honda and use Vaseline. Makes more sense now. Jk
Would guess it comes with 2 standard gaskets to be stacked because of cost and availability. Would also guess that if it leaked the way the suggest to assemble that you'v had found people screaming about it in your online instructions search.
Na never owned a Honda not even a bike, Supra is more like it. Funny thing is no one complained about leaking and seems like people have it in both ways, only leak complains I found was regarding to the bulkheads on the drains of the external box. I never used an external overflow, all my other tanks are just drilled on bottom. This will be my first so we'll see once I get my sump finished, been cutting like one teeth a day for my baffles lol. Prolly be done in another year before I am at Filling her up.