Question about PD status of some scores...

[valarking]

These are marked as Non-PD US:
http://imslp.org/wiki/Complete_Keyboard ... C_Orlando)

I am curious as to why this is, seeing as Gibbons' music is just a little dated. I'm guessing it has something to do with the fact that it was published in 1924 which is inconveniently 1 year after the cutoff. That being said, is there still any argument that can be made as to their non-public domain status?

[daphnis]

Since it was published in 1924, two years after the cut-off line, it is protected in the US unless an extension was filed.