Thanks for the nice comments.
The tune of # 1 has already been identified, the Montgomery Brothers had recorded it, too.
The pianist of # 2 is inded Rowles. You never heard him sing?
The vibist of the last track is not a giveaway. For the rest, enjoy reading the others' comments.
Two issues: one is that the law states 50 years from the date of release for pre-1963 recordings. For instance: unauthorized "EU" releases of the 1945 Bird/Dizzy concert produced by Uptown in 2005 were illegal because it was a 2005, not 1945, production.
The other issue is enforcement: masters owners don't care enough or don't have enough resources to litigate. The only case I know of following the letter of the law is Germany's Bear Family going after the UK's JSP for lifting their new masters of the early Carter Family recordings, and I'd guess that both countries being under EU law at the time made things easier.