I bought a TARDIS Keychain to add to my Star Cars collection. It's really close to the right scale. I went in to a comic shop while I was in New Hampshire and there was a good selection of TARDISs. Actually the closest to 1:64 scale was on an alarm clock, but I didn't want to buy it just for that. The DieCast TARDIS Keychain was too small unfortunately.

For reference, a properly sized model would be 1.67″ tall and 0.85″ wide.