The first step in making the goggles is to sand off the flashing and the resin pour points. This can be done easily with a Dremel rotary tool and small drum sanding attachment.
There is an updated 3d printed nose peice and two odd shaped inserts that need to be added to make it more accurate. The can be glued in place as show in this photo.
Once glued in place, a filling putty like Bondo can be used to fill in any gaps and then be sanded smooth.
These videos are unedited so they are a bit long but I think the info in them is worth seeing.
Below are some photos of how the buckles are attached.