As of now I would definitely get it weighed and measured at a local tackle shop with certified scales.

Now I don't have the heart or desire to take a bass thats 12 inches to 6 pounds, but something that big is once in a couple hundred lifetimes up here and I would have to put her on the wall. There's always the side that says put it back to let it spawn and pass down its genes, but a fish that big has spawned so many times I wouldn't be sure how many more years it would have to live to do so.

I know that southern strain bass get to about ten pounds in ten years so their northern growth rate would be much slower giving the bass a couple more years history to spawn.

So my answer would be taking it to a local shop with certified scales.