I made a variety of fountain pen & ink accessories so check my makes for other stuff.
First, I have not test printed this. So please report back if you have and your results. I'm happy to make revisions.
Second, I made accessories for inks I have on my desk at work, namely Noodler's 3oz bottles and Diamine 30ml bottles. If you want something made I'm happy to do it, I'll need you to take measurements though and send/post them for me. For whatever reason the mess that is thingiverse doesn't alert people when comments are made. So hunt me down on reddit r/fountainpens if you want to see it done anytime soon at this link: https://www.reddit.com/r/fountainpens/comments/onnyso/3d_printable_accessories/
This model is designed to hold 3 bottles of Diamine 30ml ink and 3 pens (approx 13mm or smaller) such as the TWSBI ECO. There is a hollowed bottom version and a solid bottom version. NOTE: The non-hollowed version has larger pen holes for use with larger pens.