I designed (er...well, I didn't design them...but traced) some wood type for Chank many years ago:
https://www.chank.com/shop/detail/3/font_packs/19/blinctype_letterpress_fontpack/
Tho...$250 for the set might not be close enough to free.
This company sells scans of wood print scans:
http://www.withoutwalls.com/
A nice set at Veer:
http://marketplace.veer.com/font/weathered-woodtype-pack-det0000303
You can often find Creative Commons licensed stuff for on Flickr:
http://www.flickr.com/groups/woodtype/
A few wood-type-esque fontsquirrel options:
http://www.fontsquirrel.com/fonts/list/keyword/wood%20type
Wood Type Revival has some VERY affordable options (around $15 each):
http://www.woodtyperevival.com/t/fonts
Not full type sets, but Briar Press has a nice online set of one-off initial caps and decorations for download:
http://www.briarpress.org/cuts/
The Lost Type Foundry is a newer foundry that's adopted a pay-what-you-like model which is really nice. Not wood-type per se, but some that are evocative of the era:
http://losttype.com/about/
But your best option (or, at least, the option that's most fun) would be to find a local shared book arts/printing studio/organization and print your own! Looks like Portland has this one:
http://www.em-space.org/em-space/?page_id=323