The belt/roller mount is the same as yesterday, mirror reversed. Assemble as before and add to left side of pen rail a few cm from the end. Exact position to be determined later. The rollers should be on the bottom, as on the right side of the rail.
https://cdn.masto.host/mastodonart/media_attachments/files/112/615/809/632/752/415/original/351e93e94b37d74d.jpeg
https://cdn.masto.host/mastodonart/media_attachments/files/112/615/809/845/728/519/original/b8fc4f4ba550644a.jpeg