Gday mate you could easily repair that, what you need to do is cut away the broken glass into a square or round so that only good glass is left, looks like a 40mm square should get rid of all that damaged glass.
There are 2 ways of doing the repair ;
1: go to the local boat builder an buy a T nut stainless steel with a thread to match your bolt looks like 8mm or 5/16th then cut a piece of ply wood to the 40mm square you have cut out , ply @12mm thick then just cut the foam so that the wood just sits under the origanal glass put a hole in the wood to accomidate the t nut smash the t nut i to the wood and glass in the board with several overlapping pieces of glass over the ply and other bolt holes , be sure you sand the area first to get a good key. Aralite no good you need west system or other epoxy soler res ok too.
2: cut the broken glass out then sink nut back in board and glass over over all the nuts you will need probably 18oz thick of glass (3X 6 oz)
Then once set 24hrs drill and tap threads in the nuts.
Easy
