was "production next" Kikuchi's personal alias or the name of a sakuga studio?

At that time, Kikuchi belonged to Studio CAM.
Also, although it may be accidental, the title of his first artworks is “The ‘NEXT’ GENERATION”.

Btw, Hideki Tamura(田村英樹),Takuya Wada(和田卓也),Mitsumasa Kimura(木村光雅),Masaru Iijima(飯島傑),Takahiro Omori(大森貴弘),Koji Sugiura(杉浦幸次) and Michitaka Kikuchi(菊池通隆) were members of Studio CAM.
Tamura's animation style was a great influence on Kikuchi and Omori.

yeah, it was a dumb question... Now I'm thinking the text refers to Persia, which started around the time Mami finished, and the characters on the truck could be early designs of Persia and a kappa