uhhh, that indeed is a mess
i fiddled around on it forgot to save it but you can clean up a little without digging into the whole structure and how it was made, by just duplicating the boarders here as indicated. you may have to use mergeEdge first then dupboarder, one needed match with merge to create a continuous curve and maybe use fitcrv on them befor using sweep. then use Sweep2 with the curved curves as rails, that gave me a pretty one surface only surface. edgesrf and networks srf all created a warped boarder.
you can also use fitSrf on the surrounding surfaces with the same degree and 0.01 tolerance
to clean them up a bit.
generally the topology could be rethought a little, for example why would you have 3 sharp edges pointing towards the purple surfaces but one points into a straight edge as seen on the picture on the upper right edge of that red line.