wing tank question

I'm rebuilding a KFIII orginally completed in 2002. It has two wing tanks. The odd thing is that they are different. One is black and appears to have been coated with kreem, the other one is a grey color and not coated. They are both fiberglass but appear to be made from different resins. Exact same size and shape. They are plumbed into a comon header tank. Anyone have any ideas if there was a change in tank materials in the late 90's when the kit was shipped ? Just wondering if I need to be more concerned about ethanol in one or the other.

Thanks

there was a discussion not too long ago about fuel tanks . i dont know how to link to it but you can search for it . it was titled fuel tanks and ethanol . both of my tanks were gray , i replaced one last winter and the new one came unpainted , just fiberglass looking . before i installed the new tank i filled and painted the top with epoxy primer as to smooth it under the fabric . my kit was purchased in the early 90s
you can always call mcbean for the straight poop on the tanks