They (Concord/Rounder) have a mailing list. Have not seen anything
of the traditional folk material. Someone thought some is available streaming. IMO the great value of the CDs were the extensive annotations in the accompanying booklet.
The secondary market has many of the "good stuff" - but sometimes at
exorbitant prices.

Amazon has a lot of CD-R reissues of old albums (not rounder), execrable quality, with nothing for notes, sometimes not even a track list. There
was a Cuban music album in the Columbia Legacy series with extensive notes which is available on Amazon as a CD-R but no notes. And the product description gives no hint these are inferior offerings.

I have no idea what the market is for this, obviously not enough for Concord to keep them in print. Wonder if downloads which include
the booklets in PDF format would have a market?

Cheers, Thomas.