You're probably not going to find a MINT condition Filco on classifieds.
The Keyboard Company sells mint condition Filco's and they ship to the US, but it'll cost you upwards of $175 with shipping.
You're better off looking for a like-new board on here. Keyboard enthusiasts such as the ones on GH tend to not kill a keyboard they're selling most of the time, at least from what I've seen.