I've messed around with those boards and have not been able to solder the IR board back to the main board because there is no space to get the iron in there.
As Doom mentioned it is VERY common when you crash straight down for the glass to break and the IR sensors are practically sitting against the glass so what happens is the 4 solder points break on the main board underneath as the IR board is only held in place by those solder points and 1 screw. Really bad setup.
You can make it a bit stronger if you add some hot glue to a few other points between the boards.
Now I did manage to repair one by soldering small wires between the boards small enough gauge that the wires will fit between the boards.
I know this doesnt exactly help what you are trying to do so sorry about that. I dont have an extra main board either.
When I was buying up parts drones on Ebay really cheap I learned to avoid buying one that had the bottom glass broken because the IR solder points were usually broken too which wouldnt allow it to fly. You can check to see if there are any for sale right now but I think you said you were not in the states.
The breeze will absolutely fly without the 2 glass pieces. In fact, some have reported it works better. If you try to fly indoors and it wont take off it's likely the bottom sensors are showing orange or red and you just need to shine a flashlight underneath it to trick the sensors. I think since the IR sensor glass is tinted it doesnt need as much light to take off. No idea why the glass is tinted but Doom likely knows.
Thought I would add that with the bottom cover off you can see the 2 solder points right next to the IR board that the battery is directly wired to and that's the point i solder wires to to add lights. Those solder points usually need cleaning and a hot iron to solder to. I solder then add a bit of hot glue to make sure they cant move.
It's not hard to work on the breeze if you have thin nimble fingers. Major pain if you dont.