I picked it up at an independent shop in Blue Island. It's a hike for me, as it would be for you, but I was buying an undented, newly painted tank from him for my GPz, and I was in the shop. I would think you should be able to get it elsewhere, though. If not, I got it here:
12424 Western Avenue
Ask for Guy (he owns the place, or at least runs it)
The info on the package says:
Reno, NV 89511
Let me know if you can't find it. I'd probably be willing to share this if you need some. I used a surprisingly small amount of it.
Not sure what this Methyl Methacrylate is, but it's some pretty nasty stuff, some kind of acrylic monomer. Any chemists out there want to explain?