The tips are starting to come in, and we are endeavoring to follow up.

Even if you wound up at a dead end, The Caucus still appreciates the effort. That is what crowd-sourcing is all about.

Here is one, for example, that came in from Joe Wilson, the creator of a popular television series on the Internet, “Vampire Mob”: “Just for kicks, I searched the records of the United States Patent and Trademark Office by owner name — Glenbrook L.L.C. — and found no records.”

In a follow-up e-mail, Mr. Wilson added, “I used to be a P.I. — I love the hunt!”

Thanks Joe!

For readers, who had not read the earlier post, you can read about our experiment in crowd-sourcing here:

Readers, we would like your help.

The Caucus has been busily scouring the most recent “super PAC” filings with the Federal Election Commission, trying to identify donors whose true identities remain shrouded in mystery.

In theory, super PACs are supposed to be transparent, because the groups must periodically file reports on their donors with the election commission, but some of the contributions have been made through limited liability companies and other entities that seem to exist only on paper.

The Caucus has been going through corporate records, working its way down a list of mystery donors, solving them one by one. A $50,000 donation to the pro-Romney super PAC, Restore our Future, from “Sareli Investments” last September? Tied to Mark S. Siegel, chairman of the board of Patterson-UTI, an oil and natural gas drilling firm.

A $100,000 check from “JHJM Nevada I L.L.C.” made out to the Democrat-aligned Majority PAC last June? Connected to Stephen J. Cloobeck, chief executive officer of Diamond Resorts International, a destination resort business.

But at least one major donor remains unidentified: “Glenbrook L.L.C.,” which made a $250,000 donation to the pro-Romney super PAC last August. There are others for whom we just have a few sketchy details.

This is where The Caucus is looking to throw open its reporting process and ask for some crowd-sourcing help.

The address listed for Glenbrook in campaign finance records is 3 Lagoon Drive, Suite 400, Redwood City, Calif. But a visit by a reporter to that location found it occupied by a certified public accounting firm, Seiler L.L.P. It is unlikely that the company is the actual source of the donation; instead, it probably helped file Glenbrook’s paperwork, or keeps its books. A company official told the reporter that it could not discuss its clients.

Corporate records turn up at least seven different Glenbrook L.L.C.’s around the country in Alaska, California, Colorado, Connecticut, Kentucky, Nebraska and Washington.

The only one registered with the California secretary of state is located in San Francisco and is connected to a wealth management firm, Monte Vista Management, which serves descendants of the Levi Strauss family. But Morton Pactor, who manages the office, said in a telephone interview that his firm and its clients had nothing to do with the donation. A spokeswoman for Restore Our Future declined to comment on its donors.

This is where readers can help. Checking different kinds of business records – like certificates of incorporation, articles of organization or annual reports — filed with secretary of state’s offices in different states has been key in resolving other donors’ identities. Searching campaign finance records by employers, which can be done with the Center for Responsive Politics’ donor look-up tool, has been helpful in providing clues as well.

There is also, of course, just creative Googling.

While Glenbrook is The Caucus’s biggest outstanding mystery among super PAC donors, if readers have information that will help us fill out the biographies of any of the donors that we have identified in our ongoing interactive feature, please send them as well.

Have a tip on the donor’s actual identity? Or love poking around in public records and want to help? The Caucus will take all suggestions, morsels of information and leads. If you want to be credited, we will. If you want to remain anonymous, that is fine as well. We promise to protect your confidentiality.

E-mail us at campfin@nytimes.com.