Mikael Uhlin's Marxology @ marx-brothers.org

Duck Soup - Paramount Movie Parade

Like most other film studios, Paramount launched a series of radio trailers in the early 1930s. They were called The Paramount Movie Parade and the first two promos in this series from 1933 featured highlights from Duck Soup. As the film was still in production at the time, both promos offers a lot of out-takes and an insight into the making of Duck Soup.

The first promo lasts 12 minutes and 33 seconds. It opens with music previously used for the Monkey Business-promo a couple of years earlier, probably because Duck Soup's title music hadn't been recorded yet. The Marx Brothers are presented as Rufus T. Firefly (Groucho), Chicolini (Chico), Skippy (Harpo) and Bob Firefly (Zeppo), son of Rufus. When the film was released, the characters of Harpo and Zeppo are renamed Pinky and Bob Roland.
The clip from Firefly's inauguration is an alternate take with background music, variations of inflections and some subsequently deleted lines. For example, Firefly comments on the reception; All this for me? That's how you throw away your money. I'd rather have a good box of cigars before dismissing the guards.
When Mrs Teasdale asks Groucho to follow in the footsteps of her late husband, the promo adds a line later deleted; Without my husband, I have only you to fall back on.
There's also an additional exchange with Ambassador Trentino:

Trentino I bring you a message of goodwill. On behalf of my president -
Firefly I won't be a half of your president. I'll be the whole president or nothing.

In the radio trailer, the song Just Wait 'Til I Get Through With It has an added interlude with a bass singer, followed by a bluesy trumpet. There's also an instrumental version of the song which isn't in the film.
Firefly's meeting at the House of Representantives offers one extra line, but there's also a deleted sequence before the conversation with Chicolini;

Zeppo It's that's infernal peanut vendor, Chicolini.
Groucho Well, chase him away from the building. Get rid of him if you have to use violence - and when his back is turned, get me a bag of peanuts.
Zeppo I've tried to chase him, but it's no use. He won't go.
Groucho Oh, he won't, eh? We'll see about that. Send for Firefly at once.
Zeppo But you're Firefly.
Groucho Never mind, then. I'll get in touch with him myself.

The first promo ends with alternative versions of the Freedonian National Anthem and the Heighdy-ho-section of The Country's Going to War.

The second promo lasts 13 minutes and 52 seconds. By this time, Paramount has recorded theme music for the program and this clip also features the actual overture from Duck Soup, although with slightly different duck effects. By now, Harpo's character has no name, he's just "a spy", while Zeppo's character is simply Bob, Firefly's secretary.
The Vera Marcal-character doesn't appear in this clip but is introduced as Trentino's niece. As Glenn Mitchell points out in The Marx Brothers Encyclopedia this is "a designation traditionally used when checking into a hotel".
This clip takes up where the previous broadcast left off, as Firefly offers Chicolini a cabinet position as Secretary of War. Before asking Chicolini about the standing army, there's an additional "Say, wait a minute!" from Firefly.
There are a few extra lines from Mrs Teasdale's garden party and also an alternate take of the song The Country's Going To War/All God's Chillun Got Guns. It's less tightly performed than in the final recording and Zeppo's "How we'd cry for Firefly"-solo disappears into the chorus.
The battle scenes contains an extra line from Groucho:
"Chicolini, I used to think you were two-faced, but you can't be, or you wouldn't be wearing that one!"

Both Duck Soup-promos from The Paramount Movie Parade are available (among several other items) in Real Audio on Frank Bland's Why A Duck-site, in the Streaming Audio Files section.