I Googled "Sheet music Six Ribbons" and found a bunch of results.

This is the first site I looked at:

Six Ribbons available to buy for $8 (Aust dollars)

Probably lots more choices & prices if you check out the search results.

In my opinion, and as an ex-librarian, if it's still in copyright it's good to support the artists/songwriters by buying their sheet music, so that they can produce more songs.

Helen