I polished both my frame and swingarm on my ZX7 and boy was it a job! I started by using very fine sanding discs on a drill to sand off all of the 2 coats of paint. Also the areas down near the lower motor mounts have a rough cast finish and have to be sanded down smooth below the paint.
Then the weld joints have to be stripped. I later found it easier to use a product I got at AUTO ZONE called aircraft stripper to soak on the weld joints then use a soft brash brush in the drill to strip the paint off the weld joints versus sanding these down, which I don’t recommend. If I had to do it over again, I would use the aircraft stripper exclusively on the swingarm. Place swingarm in plastic box and saturate with the stripper. I also found this stripper to work great on the clutch cover which polished out nicely. I had a customer who we removed his engine for building and at the same time stripped the bike down to the bare frame and took it to GUY IN Atlanta called BUFF BOY ROY, he did a beauuuuuutiful job on the frame and swingarm, and charged 500 dollars. I have never chromed these items but it would seem to me they would have to be completely stripped as well. I did mine with just bodywork and tank removed and It looked just as good. Now, this is not something to enter into lightly if you choose to do it yourself. The best polish I have found is something called EXTREME, reminds me of a product called nevr-dull. This stuff works! It is easy and prone to scratching, just wiping a rag across it will scratch it. However,mine turned out great. Won Best in show at Marietta Motorsports Sport bike show in 1995.
I recommend paying some one to do this as I WILL NEVER DO THIS AGAIN, no matter how pretty it turned out, as the truth of the matter is, its like jetting flatslide Carbs, your never quite satisfied with it and are constantly working on it. But make no mistake, a polished 7 frame and swingarm, sure look nice.