Little more to it than that;
Didn't the Russian Fleet show up in NYC and San Francisco and offered to help? I believe the Union said, "Thanks, but no thanks."
As has been said, the Russians sent two squadrons of cruising vessels (steam frigates, corvettes, and sloops-of-war, essentially), one of six ships (including at least three frigates) to New York and one of five to San Francisco, in October-November of 1863; coupled with the Russian cruisers on station in the Med and elsewhere, they certainly could have posed problems for the French if they (the French, that is) had (rather quixotically) intervened in support of the Polish rebellion in the same period.
The liklihood of the British doing anything about Poland in 1863 is about nil; they didn't intervene when the Baltic exits were actually threatened in 1864, so the idea they ever would have considered it seriously in 1863 over whose flag flew in Warsaw is pretty questionable.
That being said, the Russians kept their ships of the line and similar types at home in the Baltic, to pose a deterrent to any French desire to imitate Napier, Dundas et al in 1854-55 (although presumably the French Army could have provided the 10,000-strong landing force for a combined operation in the Baltic, unlike the British a decade earlier.)
Likewise, the Russian cruisers certainly would have been capable of doing
Alabama-scale damage to the French merchant marine, and the fact the French had obliging sent the equivalent of a reinforced army corps to play round and round the rugged rocks with the Mexican nationalists probably had something to do with NIII's decision not to try and force the issues - especially with the de facto Russo-Prussian alliance of the Alvensleben agreement.
The Russians were in both US ports for their own purposes, but they were welcomed for obvious reasons, as well; and the Russians, in fact, indicated that any effort by a semi-pirate like the
Alabama to threaten US or neutral interests in waters near either city would have been met with force. Popov, the commander of the Russian squadron in San Francisco, said as much; excess of zeal or not, it was said publicly.
One interesting question is if Brig. Gen. John Turchin could have made it to the party in NYC; he was commanding 3rd Brigade, 4th Division, XIV Corps, Army of the Cumberland that fall, but might have made an interesting envoy...
Here's the
Disunion column:
http://opinionator.blogs.nytimes.com/2013/11/08/the-russians-are-coming/?_r=0
Some interesting details there, including (yet again) an illustration of the "US fought the Civil War with one hand behind its back" truism...
All those cooks and waiters...
Best,