The word for “zebra” in the Gnomish Lexicon of the 1910s was raibrog or ribrog with a feminine variant raibros, a combination of G. raib “striped” and G. brog “horse” (GL/64).
Neo-Sindarin: I’d adapt this word as ᴺS. raebroch for purposes of Neo-Sindarin, using the later word S. roch for “horse”.
A word appearing as G. theres “a tie, ribbon” in the Gnomish Lexicon of the 1910s based on G. ther- “to tie” (GL/72).
Neo-Sindarin: In Tolkien’s later writing, √THER meant “sew”, but I think ᴺS. theres “ribbon” could still be based on the later meaning of this root.