Multiple Passports Disclosures in Visa Application

As it is often reported, this question is way above the pay grade of most of the posters here. None of us have faced such a complex question and, personally, I would not trust any answer that you receive. Most will be just guessing. This is very technical types of question and I think a good immigration lawyer -- might be useful. Or someone who specializes in obtain Russian visas. This is not the area for casual information.

First off, the question is NOT "What entry or exit stamps or visas for what countries are in the passport you will have with you on this trip?" The question is very simple "What countries visited in the last 10 years." List them all. If Russia really wants to know where you have been, they will find out. Leaving off information of the application will not go over well if it doesn't match what they find.

Beyond that, I have to agree with Frank. This is too seriously legally entangling to get an answer here. This requires someone with experience in getting Russian visas approved for their clients.

While I agree, as almost always, with Frank, it seems a very simple closed question. Where have you visited in the last 10 years. Not an open question amenable to partial disclosure. Especially in the light of your previous visits, even if under a different passport.

I've never heard of a passport belonging to a company not an individual.

That's one interesting organization you've worked for!
In any case, seems pretty straightforward to me - list all countries visited over the past ten years, travel on your regular US passport.
Most importantly, have fun!

I agree with the sentiment so far, keep it simple, your passport (other than country of issue and expiration) is not an issue. Give a fair accounting of your travel over 10 years, and present your current passport, past passports are not a concern.

As an example, if I were issued a new passport last month, due to losing the old one...I see no need to provide extra details on that passport, only my current one.

Also, if you are hinting at maybe not including travel to Belarus, Ukraine, and Georgia (I can see the concern) I would advise against that, better to be honest, even if it leads to a rejected Visa, than to deceive and wind up with potential serious issues once in Russia.