You speak of audio recordings "from archives". What archives would those be? Presumably you have the permission of the archive owners to make transcriptions for publication; presumably you also have permission from the recorded singers, or their heirs or assignees? The fact that a song is considered generically "traditional" doesn't of itself place an individual person's version or performance of it in the public domain. Ask the School of Scottish Studies, for example; they have encountered all manner of associated issues.

Doubtless you have already taken advice on the legal implications of all that, and will know that the fact that you are a "small community music project" doesn't exempt you from the same obligations regarding copyright and the payment of royalties that would apply to a commercial organisation.

Please do keep us posted. It sounds like a very interesting project.