This is a cryptic crossword jigsaw fill: the clues are listed below, grouped by length (the only clues to have length in the standard parentheses are those having two words) and in alphabetical order in each group. When they are solved they can be arranged to fit in the grid in exactly one way.
Once the grid is filled, the numbered squares will spell out, in order, the expected (though fictional) feminine noun for a member of a famous group. Solvers should correct the spelling (change exactly one letter) to be the name of the group (this will produce real words in the grid, though arguably one of them is oxymoronic). Solvers should also highlight three surnames in the grid, of members of the group, and indicate which single letter should be changed elsewhere in the grid to find a fourth surname (sadly this change does not create real words).
Design a current for Malta Tropical bird nests in Madagascan ironwood
Dye a duck Half a square metre of paper is perfect! (1-3) Schematic's second page missing a key... ...tone, for example, laid out Last two thirds of push for small defense No second impact to back of knee Edmund's white with age and Henry's rather less masculine My intention broadcast by Man, for example Once illuminate starting letters in manuscript notes Indian gardener -- bad one Friar's opposite is mostly Capuchin State occupied with Frozen Snowman Dialect once supported by saint No mate for milky white gemstone? Local leftovers rot badly, son After seconds of spiced cake, essay Stilton
High priest sets volcanic rock above man American paid up for desired missing wife A psi-sigma initial segment defines greatest orbital distance from centre (Informal) Sound of car maker getting nothing Demeter covers with wax... ...time after time, O Muse! Lots of LA hormone takes Venetian to height of poetic inspiration Stinking tide stirred up after most of reef is destroyed Carry back: private secretary swallows quickly Deflection into pocket -- Fagin offers a hiding place (2-3) Calibrate without outliers -- sign of balance US Saltpetre can reverse heading, right? Celtic letters found in 'Van Gogh -- a memoir' That woman, Vanessa, extremely indicates absence of vowel
Debauched beasts; most, worthless Hobbesian companion?
Like thin plates tangling right animal He examines and corrects reivers' discombobulation
Trace of life essential for glowing particle (5,5) Parrot plague-host is iron-addled