I'll put my Zaino hat on for a moment and recommend a product of theirs that I recently tried: Zaino PC-Fusion. My black 91 was suffering from a case of swirls, so I decided with a recent Zaino order to give the Z-PC a try.
I set up my 1000 watt halogen lights in the garage and couldn't believe how bad the finish looked. Swirls everywhere. Could be due to my wash mitt, perhaps my aging cotton towels, who knows? I applied the Z-PC by hand according to their instructions (you can also use a Porter Cable), and amazingly, the Z-PC did an excellent job of removing the majority of swirls.
Afterwards I applied a few layers of Z-2 and Z-5 and am back to my standard application procedure for Zaino. I've also invested in some quality micro fiber towels to help minimize future swirling.
I'm quite pleased with the results and wouldn't hesitate to recommend this product. It's not something you'll use often but for my 91 it did the trick.
Sorry, haven't taken any pictures recently so I don't have any before/after photos.