ahh, I so want to participate in this challenge, but I have some exams lurking ahead.
And *pop* here they are angel and devil on my shoulders...and both are telling me to participate 

do you remember the name of the shop?
Or the street where it is?
Then you could just write them a letter/mail or phone them,
most little fabric shops are were friendly and will send you the fabric or tell you were they got it from.

Very inspiring!
I love the mask, its 

The first thing that comes to my mind is the lion Grograman (or Graógramán) the "Many Colored Death" from the "Neverending story".
I dont know if and how he features in the movies, but its one of my favorite characters in the book.
And it would go so well with your hair 

But of course you would perhaps have to explain some people that you are NOT from CATS.

hm, you could paint the paper thingy inside the paper towels or glue several roles of paper together to look like a telescope.
perhaps you have a compass lying around? If not you could also draw it.

wow.
I hit this rocks,
because it rocks 

Thats so cool! 
 I have to try this!

What kind of closure have those?
If I saw them, I would surely think about buying those,
the quality and comfort of the closure would have some weight in the decision how much I was willing to pay.

Like some other posters said, i like it when people "get involved" in politics and if they show their opinion in a creative way. thats really cool.
and since this shirt was created to show an opinion and then posted, its open for discussion and this project IS political the discussion should be allowed to be so, too.
But in my opinion the discussion has to discriminate the different parts of the craft, stick to the topic and facts, allow for different opinions and stay civil.

1.there is the technical part:
Im impressed how well you managed that tubes, when I'm using them there are just blobs and my letters arent recognizable at all.
But something like pencil or chalk lines underneath each row or the printed layer underneath would help keeping it somewhat more straight next time. All in all I think its a cool way to spontaneously show conviction.

2.Then, how does your message come across?
It is clear that you are pro MCCain,
but when I started reading the shirt I thought you were pro Obama, since in the terms Hope and Change(in this context) are catchwords in his campaign, whereas Mccain uses someting like "reform, prosperity, peace"...
( I dont say Obama has the only right to use this words, I simply refer to the fact they are his campaign slogans and all over obama shirts)
This "mixup" might  increase the wish to discuss this shirt.

3.The message itself
Partly the "mixup" of the catchwords can come into discussion here,
and how much you intended to provoke or to perhaps make a statement that for YOU Mccain is standing for all this (at least in the change part )

wow!
its such a great project! Its the discworld AND you have done such a great job it loos so good.
I hit this rocks!!