Hi James,
when I did my repair I used dry wall plaster board plugs (the grey ones) and cut off the 2 "arrow head" type prongs. I drilled holes in the speaker cover points where the original locating pins were and piloted some screws into them before unscrewing them and cutting off the heads. Next I glued the blunt ends of the screws with epoxy resin into the plaster board plugs. When they had set I then simply screwed them into the pre - drilled holes in the frets also fixing them with epoxy resin, they were a perfect fit and a bit of black paint finished them off nicely
I hope my description makes sense as some photo's would have helped here but these speakers are long gone from my possession.
Chris.
The use of metaphors should be avoided like the plague. They're like a red rag to a bull to me.