I find that most places carry it, but don't emphasize it because of it's low cost. Ask the clerk, that's what I've had to do on most circumstances and they'll pull one out from the back.
I've been to 6 liquor stores. None of them have the 1783. All they have is the 1783 Black Label. I asked in every store if they have any in the back or have even heard of it. They all look at me like I have 3 eyeballs.
Methinks tis' a myth, this 1783 stuff!!