Best Mates by Chalicea

Two characters and three films they star in circle the perimeter of the grid in a clockwise direction. An extra letter in addition to those required for the solution is produced by the wordplay of every clue. These, in clue order, give an instruction to solvers. Unchecked letters in the perimeter would jumble to MY! WE SAW VANGUARD CO-STARS Chambers 2016 is recommended.

    9    Drop of ale in beer mug for native of ancient Ionia (5)
    11    He's on gym exercises and muscle proteins (7)
    12    Be woman undone, and, according to bard, conceive child (6)
    13    Painstaking eccentric fellow with 'self-build', ignoring odds (7)
    14    Old private detectives call for attention (4)
    15    In difficulties, to windward at submerged ridge of rock (7, three words)
    16    Ancient prostitute almost sincere with everybody (5)
    18    Adult in vehicles for transporting miscellanies (4)
    19    Following a sound of disapproval I finally wrecked drainage channel tide gate (8)
    21    Feel humiliation once when hoax takes in a European (6)
    23    Performing group is sadly scattered with alto and soprano missing (6)
    24    Hindu philosopher welcoming hospital letter long ago (4)
    28    Was introduced to a Dutch alcoholic drink (4)
    29    In the past to extend the distance swum, for example (6)
    31    New fracas damaged US motor sport (6)
    32    Ponder about a truncated hollow chamber on a major blood vessel (8)
    33    A tree trunk having enough strength (4)
    37    Heartless cold associate in common prison (5)
    39    Observe husband fuss long ago over Chinese trees (7)
    40    To free from trouble, partly made safe going west (4)
    41    Miserable farthing for guardian of Sikhs' holy book (7)
    42    Company in France set up English altar candle (6)
    43    "Encore" mostly amid endless absolute expressions of praise (7)
    44    Tenor involved in short revolutionary engagement (5)
    1    Large commercial ship's left unable to move (5)
    2    Seizes unwrapped gun, it's for proceedings in courts (8)
    3    Highly skilled to engage in contest involving left hand (8)
    4    Stop essentially evil-tempered, spirited horse wheeling (5)
    5    Too bright in Glasgow to propel boat between river and railway (5)
    6    Ordinary violent rage is hard, cruel and ugly (7)
    7    Cinema half abandoned; fine one in Cannes - not seriously! (5, two words)
    8    Mighty wave must finally astound friend from Guadeloupe (7)
    10    No longer refused crude rubber found in lump (6)
    17    Jug's grim, upset on top of head of queue (4)
    20    Tipped over bags containing old tuberous plants (4)
    22    A venomous lizard turning up an aquatic organism (4)
    24    Extremely silly to mostly dispense with pages in limp book binding (4)
    25    Aging celt, in confusion, coating things with sugar (8)
    26    Men's icier terror losing all restraints in Spanish event (8)
    27    Drummer's retro beat taken up, not keeping time once (7)
    28    Mysterious mountain spirit (7)
    30    Way of trapping slippery characters in Spain and the Spanish dissenting clique (6)
    34    Whopper! An eastern climbing plant (5)
    35    Clumsy locksmith dropping scattered kit is a klutz (5)
    36    Shakespeare's chief witch, malignant hag ripping out heart (5)
    38    Catch gold antelope (5)
To enter this competition, send your entry as an image or in list format including the result of the instruction to before 8th February 2021. The first correct entry drawn from the hat will receive a book from the Chambers range, which has been donated by Chambers.