They did indeed have a Metal-Typer machine as once was relatively common in places where you might buy souvenirs of a given place. For fifty cents, you get 32 characters (but you'd better leave it at 31 unless you want the last and first characters to run together). I made one.
Shown here with a quarter for a size comparison is the anodized aluminum medallion, which reads SAN JOSE IN 2018-WORLDCON 76. The image in the center is an outline of the Winchester Mystery House, and the reverse says WINCHESTER MYSTERY HOUSE SAN JOSE CALIFORNIA.
While I was there, I took a couple of pictures of the House itself.
Not wanting to pay admission today, I simply held my camera over the fence for this shot of the front of the building.
The building is a registered historical landmark, and well worth the visit. I've been through the tour four times, including once on one of the "flashlight tours" done at night.
If you're still undecided about which site to vote for for the 2018 Worldcon and are wondering what there is to do and see in San Jose other than the Worldcon itself, this is one of the places I think everyone should go see. It's not walking distance from the convention site, but it's a relatively easy public bus ride, and I suspect that if there was enough interest, we might be able to arrange for transportation for a group to go see it. (I'm not in a position to commit to that! I can't guarantee it! I'm not volunteering to organize it!) But if you can go and visit the house and gardens, try to do so.