I'm a long-time car modifier and restorer. I've used a wide variety of metal polishes over the years, including those mentioned, and in fact have most of them in my inventory.
I recently found my very first centerfire pistol (which I thought had been stolen): a Series '70 1911, that I bought with a .22 Conversion Unit that had an aftermarket nickel finish to match the OE bright nickel on the pistol itself.
I had this pistol since I was a kid and all the summers on the farm using it pretty much every day had taken its toll on both finishes, especially the less-robust aftermarket finish on the .22 Conversion Unit. I was convinced that it would require refinishing, and trying to clean it up with Mothers only confirmed that thought.
But my mind went back to some vintage car parts we'd saved with Happich Simichrome Polish, so, as a last ditch effort I ordered a tube from Amazon and gave it a shot. Not only were the results amazing, but it was a lot easier to achieve a far better finish with Happich than it was to achieve lackluster results with Mothers.
I don't mean to disparage Mothers-- it works fine on allow wheel rims, etc. And I don't make a single cent by touting Happich, but seriously-- the stuff is bloody magic! If you have a finish that'll stand up to a true metal polish, Happich is absolutely worth trying. Not only does it provide the best results of anything I've ever used (including Flitz, which is quite good), it's so easy to use it cuts your labor time by 2/3. It really is that good.
Now, I notice CA won't allow it to be commercially shipped there, so even discounting their nanny-state antics, that suggests it might be best to use vinyl gloves when using the stuff, even though I went commando when working over my Conversion unit because I was so stoked by the results that I didn't want to stop to put on gloves.
Like I said, I get nothing out of touting the stuff, but it is so incredibly effective on nickel I gotta at least encourage you to give it a try.
BTW, nice score-- I love nickel revolvers because they're so much easier to clean.