I would want to see pictures of yours first. It's easy to think that two items look the same given general form and materials. But, they can often be very different in the details.
...I will say though that is not a corn knife. corn knives are strait, wide and flat. they taper out from the base and have no tip (just a flat edge that meet the side edges at an acute angle).
...And tobacco knives are, what ever someone chooses to use for tabacco cutting...typically short to downright stubby though as it doesn't take a lot.