I first attempted to solve this on my own by simply starting in the Mudhrid system and using the in-game galaxy map to plot an economical route to HIP 22550 (the the main system for the Marlinist Colonies).
This gave me approximately 15 systems between the Mudhrid system and the the HIP 22550 system.
It turns out the right system is "Trianguli Sector GW-W B1-0 1 A" which wasn't one of the systems along the route plotted by the in-game galaxy map.
DragoCubX had an interesting approach to solving the mystery by making a list of viable systems (within 37 ly jump range lf each system between Mudhrid and Trianguli Sector GW-W B1-0 1 A).
I'm not sure what how DragoCubX created the list. It would be great if one of these map DB websites had a way of producing a list of systems with x for a reference system or even for route.