They appear to have some compression I would guess from the file size.
My calculations would seem to agree that you are likely correct. In the Glen Gray album there is ~ 59 minutes of tracks, and at ~ 10MB per minute for uncompressed 16/44.1 that would be ~ 590MB uncompressed.
In my own ripping and converting, I have seen compressed lossless FLAC take about 50% to 60% of the space, but have not yet seen it go below 50%. At 50%, the album would be ~ 295MB, so at 216MB total for the Glen Gray album, it would appear that there may be some lossy compression as well.
Steve