Need help identifying 19 liter tank

[markb]

I have a tank that I'm trying to confirm if its a nineteener.  For comparison here's a pic I got off this site.


Here's the one I'm trying to identify.  Looks pretty close to me.  Were there other tanks, CB450 maybe, that could have the same bottom?


If it's the right tank the badge areas have been filled in.  If so, how hard would it be to remove the bondo.  I'm going to remove the paint today to see.  Maybe its the stripe but the shape seems off a little.  Is the top half of the tank the same as the later tanks?  


There are no wrinkles looking through the filler hole but if you look at the first photo there won't be any.


The tank has been painted but the color on the bottom seems to match the candy red which would indicate an early CB750.  Is there a way to positively identify a nineteener?