WASHINGTON (AP) _ If you were casting a movie about the Keating Five, would you pick Vincent Price to portray Sen. Alan Cranston? How about Robert Duvall as Sen. Dennis DeConcini?

And who would play Charles H. Keating Jr., the former savings and loan executive who raised $1.3 million for five senators and persuaded them to help in his fight with thrift regulators?

Would you believe Jimmy Stewart?

The staff of Roll Call, a privately owned newspaper that circulates on Capitol Hill, ran a fake full-page ad Thursday to announce a new movie: ''The Keating Five.''

It's a spoof on the Senate Ethics Committee hearings now under way on the ties of Cranston, D-Calif., DeConcini, D-Ariz. and three Senate colleagues to Keating - who owned the failed Lincoln Savings and Loan.

''First there was 'The Magnificent Seven' ... then 'The Dirty Dozen,''' the ad says. ''Now ... the U.S. Senate, in conjunction with the U.S. League of Savings Institutions, presents a Constituent Services Inc. production of 'The Keating Five.'''

While many followers of the case were chuckling over the ad, the committee remained at work behind closed doors to hear James Grogan, a top aide to Keating.

After two days of testifying in private, Grogan was told to appear Friday in a public session. He's testifying under a grant of limited immunity.

Roll Call writer Craig Winneker, who coordinated the project, said the newspaper staff cast the actors first, ''and then pulled out their pictures. We were amazed how much they matched.''

In addition to Cranston and DeConcini, other stars of the ''movie'' are Ed Harris as Sen. John Glenn, D-Ohio; Tom Cruise as Sen. John McCain, R-Ariz.; and William Shatner as Sen. Donald W. Riegle Jr., D-Mich.

Apparently only four members of the six-senator Ethics Committee will be portrayed.

Ned Beatty is cast as Chairman Howell Heflin, D-Ala.; Jason Robards as Warren Rudman, R-N.H.; Rod Steiger as Sen. Jesse Helms, R-N.C.; and Ron Howard as Sen. Trent Lott, R-Miss.

No actors were chosen for Sens. Terry Sanford, D-N.C., or David Pryor, D- Ark.

Cher is cast as McCain aide Gwendolyn Van Paasschen and Melanie Griffith is Cranston fund-raiser Joy Jacobson, both witnesses in the hearings.

John Candy is Ethics Committee special counsel Robert S. Bennett and Don Ho has the part of Sen. Daniel Inouye, D-Hawaii, who was a character witness for DeConcini.

Martin Balsam is Edwin J. Gray, former chairman of the Federal Home Loan Bank Board and Dennis Hopper is cast as Gray's successor, M. Danny Wall.

Mother Teresa, mentioned several times in the hearings as a recipient of Keating's largesse, would make a special appearance as herself.

There is one precaution for viewing the film.

''No one will be admitted during the final 15 minutes while the Ethics Committee deliberates,'' the ad says.