The Pink Stamps Special Lotus 30 currently has a ZF-Synchroma 5 DS-25 gearbox with 5 forward speeds and one reverse.
Below is a pdf of the service manual for the ZF 5 DS-25 Gearbox. It is from a 1980’s photocopy, so the quality of the photos is not that great.
ZF 5 DS-25 Manual
Below are the three pages in the manual with an exploded diagram of the ZF 5 DS-25.