Ongoing saga, in case anyone's interested... I went to 3 banks today and none would cash the travellers checks. They said they don't even have a way to cash them as those relationships don't exist for the bank anymore.
So no to BMO, RBC and Scotia.
The good news is that they all recommend National Bank. The bad news is I can't get anyone to answer the phone at National Bank (just like all the other banks) and it's quite a drive from me, so that's for another day.
When I phoned AmEx, they said they could start a claim for me, but then I'd get the amount in Canadian, not American. What she did say, however, is that the U.S. doesn't have the issues that Canada has for cashing these things, so I shouldn't have any problem using them in the U.S. on my next trip. That may be my best option.
Now if only Disney could take them over the phone as a downpayment on my next trip, lol.