I can do better than that, I think.  

Your Suzuki part number is 14181-45C00.  The part was constructed by wrapping a long wide sheet of of thin corrugated aluminum bellows like material and wrapping it three times around a 2" diameter steel mandrel (2.024" on sprung free ID) then wrapping thin abestos-like fiber paper around that 40 times then wrapping the OD in another three wraps of corrugated aluminum bellows material to finish out at a 2.428" OD.  Then they cut the resulting long ridgid composite tube into little 0.196" wide slices using a roller cutter to make up our little gaskets.

In inches -- 2.024" ID,  2.428" OD,  0.196" thick

In mm -- 51.42mm ID,  61.61mm OD,  5mm wide    (independent data, the part isn't perfectly round BTW)

And yes, I suspect they have muffler gaskets at a car parts place that could work and be a good bit cheaper to buy.  

Do tell us what that answer is, looking forward to knowing.

I've always thought the stock one could be a little thicker,...I'd like a bit more crush....

Remember, the gasket fits the outer edge of a flange on the end of a 1.75" exhaust pipe.  Measurements are correct, even when back checked with a simple steel ruler.

If this is a failed thing, it needs to be moved to Rubber Side Down.

Shame, seems like a gasket should be available for some larger exhaust pipes.  Diesel exhaust systems commonly use 2" pipe sizes and up.  Did your NAPA man check bus exhaust systems (school buses and such?)

Ive done this twice already. I know the auto parts store has it in the back with all there other gaskets (usually in a bin of sorts). I don't recall what the exact nomenclature is, but I do remember its off a Chevy engine and is classified as an exhaust cruch gasket. Runs about $5.