Add a 'carry thwart'?

[Howie]

I'm in the middle of restoring a 15' Old Town 50 Pounder from 1945. This canoe has a very short deck - about 10" long - and only attached to the first two half ribs whose ends are tapered to virtually nothing. I'm concerned that the deck is just not anchored to the ribs too well. Seems to me that when you hold the canoe by the deck all the canoe's weight is being supported by the rail located between the 2nd and 3rd half rib.

So I'm thinking of adding carry thwarts. Of course the problem with carry thwarts is that adding the bolt hole weakens the rails. I'd use #10 screws to lessen the damage, but still...
So I'm looking for advice. Add carry thwarts?, or not?