As the one who started the original thread, perhaps I can offer some feedback on the solution I chose.
What I did was tack together the cracked pieces with a little superglue. Then when that set up, I fiberglassed the whole unit together (from the backside). I used the suerglue first just to sort of hold everything together. You can probably skip that step depending on how adept you are at glassing. I applied the glass on the underside in double layers with a healthy application of resin and it really gave me a rock-solid fix. Then, I used Bondo paste to fill in the cracks on the visible side. I'm still at that stage, but so far it seems to be working just great. Next step will be to sand the front sides with the bondo nice and smooth and then paint them.
Of course I've got a really thick, unsightly, chunky layer of glass and resin on the back side of the covers, but you'll never see it unless you pull them off and turn them around. Might not appeal to the hardcore restorers on the board, but it surely suits this daily-drivin' fool.
BTW Total cost of materials shouldn't be more that $15-$20 US and you'll tons left over to glass whatver else comes along.
Hope this helps!!
