Show & Tell. Speed-contests. Demonstrations. Letting others use your machine/s...just a few suggestions. 

Where do you live?

Supply paper and envelopes, maybe even stamps, and invite visitors to write and post letters to their friends and relatives.

If it were my machines, I'd leave the Rocket at home too. The Sterling and 319 will handle whatever punishment a public demonstration will throw their way.

I would try to attract other typewriter collectors to the type-in, because for an event like this, the more machines that are made available for use, the more options you will have.

For example, you could dedicate a machine to each event of the type-in, one for guest book entries, another for free typing, a machine could also be dedicated to a fiction story that each typer has to add to, and maybe one just for short poems.

I also like Mr. Höhne's suggestion a lot. I think those unfamiliar with typewriters will find it an interesting experience to hammer out a page to someone they know.

Good luck!

 

Personally, I wouldn't worry about coffee near a typewriter - if I did I'd never get any typing done - because spilling coffee on a machine wouldn't hurt it. You would of course have to clean it afterwards, but that's a small price to pay and it's highly unlikely that it would happen in the first place. Besides, I'm sure the owner of the coffee shop would appreciate if the people using his space were also paying customers. 

Is there a larger city near your smaller town? If so, I'd be sure to spread the word far and wide; most enthusiasts wouldn't mind driving a bit to meet other people interested in typers. Even if you only get a few people to participate, you might just end up turning someone else on to using typewriters, and at the same time instantly double the number of collectors in your town.