I would have to see you throw both side by side to say for sure, but I would actually think that polishing the solid would make it closer to the Fusion, not further away. I have both balls. For me, the solid is much earlier than the Fusion, and it lays off more on the back end. I don't use the solid very much during league because it doesn't give me the right shape to take advantage of the wide-open conditions; however, it is fantastic when the lanes are tighter and I need read and control.
As such, I think that polishing up the solid will succeed in making it more useable than it probably is right now for you, but I also think it will make it react very much like the Fusion.