Errrrr....
Out of all my fish all seem to do fine other than a single Yellow Tang, he always seems to find the intake of my closed loop sequence pump and gets stuck to it. Someday I will spread the intake out wider. But thats another project.
As far as the brace sounds like a simple fix. If it where me I would sacrifice looks and keep the brace and drill pilot holes, cut a few small bolts to size (I have some s.s. ones that will work) sand down the 2 ajoining surfaces (the new plexi and the old euro brace) and sandwich it with the combo of the bolts to retain till the glue sets. Its a little overkill, could do without the bolts.
But you seen how much I overbuilt my hinged hood with t-5's too.. lol