well you can roll the dice and hope the other 3 stay intact... not the best option

You can cut off the elevator and relocate 4 new CA or what ever type hinges in different spots... hinges are a one shot deal and need "clean" wood to work best.

You could make covering hinges...also called gap sealing. Cut two about 1 1/2 wide inch strips of covering long enough to go across the entire width of the elevator(the hinge line). Undo the elevator control horn connection...clean the existing covering VERY well with alcohol... lay your strip of covering across the hinge line over lapping about half the width of your strip(3/4 inch) onto the Horizontal stab... deflect your elevator FULL down...take your iron(you do have one?) and tack the strip in place being careful to not stick it to elevator... once tacked run your iron over it to stick it down good...still being careful not to attach it to the elevator. once it's tacked MAKE SURE the elevator is deflected FULL down... work the covering onto the elevator by rolling it down with your iron... once it's locked down check for travel on the elevator... it should move just as far with the covering as it did without. now that the top is done and sealed down do the bottom the same way... on a 40 size plane the covering alone can be used as the hinges... you still have 3 out of 4 CA hinges holding it also

It's possible you used to much CA to glue in your hinges causing them to become brittle and break... CA hinges can fail from to much glue just as easy as not enough... more often than not it to much though.