https://www.typewriter.company/pt/products/rare-olivetti-typewriter-cartridge-ribbon-for-olivetti-lettera-10-12-lettercart-ribbon

It seems like the cartridges for the Lettera 12 are no longer available.

see also: https://www.reddit.com/r/typewriters/comments/1ov8fa3/olivetti_lettera_12/

https://www.reddit.com/r/typewriters/comments/1o8lzdm/trying_to_id_a_typewriter_from_a_video_game/

Folklore (2007, PlayStation 3)

https://old.reddit.com/r/typewriters/comments/1gu1x3r/olivetti_112_not_found_in_the_twdb/