SOS!
by Kegler

Six answers become new words before entry into the diagram, after receiving 25 Across.

SOS! grid

Across
1Endorsed speaker's not included
6Philosopher concocted a plot
9Drink sounds like a place to start
10Press me to join, ultimately, athletes with stamina
12Lieutenant obtains, at the outset, explosives permit
15Horrible seller eventually admitted to second offer
17Male, without shame, essentially, wearing headgear in town
18Experts hosting one of many dances
20Agent starts to scam provincial yokels
21Teases ones in cages?
23Bats for baseball teams
24Blame, initially, cutlets coated with unusual sauce
25See instructions
27Follows the trail of broken crates
29Competitor grasps head of poisonous snake
32Lost one mediocre grade, we hear
33Crazy mother comes back
35President arrests leader of infiltrating snoops
36Nearly plant in such a manner
37Inept loader's difficult time
39Pose a question while starting to kneel
40Cans entire bananas and fruits
41Reportedly draw low digit
42Lived with trace of deep bruise
43Extremely blasphemous rubbish
Down
1A sailor's returning collection of charts
2Island entertains a couple of theories for name
3Poems rise excitedly for those hearing "I do," perhaps?
4Chest of very large black bovine
5Threaten me, shockingly, revealing trap
6Average type of music making a comeback
7After the start, signals farewell
8Dance opens wildly, packing empty theatre
11Marmot hungrily swallowing insect
13Pioneer's one-time hype filled with history
14Stinging stock trader in plot
16Careening, reach a bit, and move like an ape
19Young lady is featured in manuscript
22South Carolina retaliates and looks for something worth saving
25Heiress ultimately put a stop to mail
26Again agrees to rules about safety, primarily
28Ali had destroyed flower
30Bewitching woman left out of band
31Strip of rubber, a stiff backing for ruler
33Ditches witty sayings about actors, primarily
34Embankments slip backwards, engulfing back of house
38Consume trimmed meats

Solution