I think its their first album released in 1976?
Ossian - Ossian
The first album, 1977. Simply called "Ossian" on the sleeve, no mention of "Celtic Music And Songs From Scotland" as named here - maybe an overseas release ?
The sleeve gives:
Billy Jackson - celtic harp, uillean pipes, whistle, vocals
John Martin - fiddle, mandolin, cello, vocals
George Jackson - fiddle, mandolin, flute, whistle, guitar, vocals
Billy Ross - lead vocals, guitar, whistle, dulcimer
Tthey produced it themselves and were hawking it around the folk clubs of Britain where I bought on in Hull in 1979