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.

Well, that's all that really matters in the end. I'm curious though; how does it now react in comparison to your Fusion?

Wow. If a polished up IQ Tour Solid truly reacted like the old Tropical Heat Hybrid, I would shine mine up immediately. I loved the Tropical Heat Hybrid. Sadly, mine cracked in half about a week after I shot 300 with it. 

As for the reaction of the polished solid versus the Fusion, I'm not surprised that the Fusion had more back end, but I am a bit surprised that it was earlier. Then again, it really depends upon the grits you used and how much polish you applied. In any event, it sounds like you found the reaction you wanted, and that's what it's all about!