>>Although there isn't a way to visualize in Moi which side is the positive normal side

Not directly but....

This trick works only with single surface, not joined, so you need to copy a one single surface from your joined object. (if you have joined object)

Click command >CPlane< and move the crosshairs along the "edge" and see what happens and cancel command..... File attached....

Other command that use normal's is>Shell< but notice, again single surface.

First method is easy....

Thanks for ....

Thanks for answers guys. I'll check those options. I've not modeled the mesh and i'ts modeled as is i.e. no time for changes/fixes nor do i have contact to initial perosn who made it but i've noticed that in past several times on some meshes from Solidworks and ProE.

As for double sided materials well that works for most of cases BUT in this particular case when at renderign fliped normals need to be emissive (glowing light) then it's not renderign in Octane so i need to make way to flip it to positive direction to be able to make them emitt light.

cheers