Could track 15 be credited to Eiji Nakamura since he is listed as Sound Engineer in the original FF7 credits? The track only features the chocobo sound effect which he likely created.
Any chance someone with a Twitter account could ask if JAMCompany (@JAMcompany) did arrange/perform Track 16? Users in other album discussions have had success with getting replies this way.
edit: maybe ask them if they want to unofficial give a title too?
edit 2: Track 6 also appears on the Beer SQ album and performer credits are listed there:
Wood Bass: Wataru Iga / Drums: Kousuke Wakiyama / Trumpet: Chiaki Miura
Trombone: Kayoko Yuasa / Alto Tenor Saxophone: Junko Kato
Mix: Tetsuya Yamamoto
Studio: Megurusoko / Engineer: Tetsuya Yamamoto
They don't seem to be an associated group, which is likely why they weren't given a performer's credit like the other tracks.