Wiley (ish) Window build

I was rather perplexed building a wiley window. I reviewed all of the posted and watched the videos, but must admit to some general confusion. Determined, I decided this weekend I would build said window for better or worse. I plan to build 2 in the lower half of the truck camper. The first is pictured in this little sad tutorial. The second will be in the lower door which should give me some rear view mirror usage?
First I cut out the plywood and glued up some 1X2s to frame out the window. Sounds good until I read the window should really overlap the upper frame by a couple of inches. Much to my dismay I was able to break off the 1X2 with minimal damage to the plywood.
Next I decided the 1/4 inch plywood would not be strong enough to seal the window against the wedges so I glued up some additional 1/2 boards around the frame.
Once that was done I knew I needed to make an angled window seal. I used 1/2 wood for this and hand planed a 25 is degree angle.
First I cut out the plywood and glued up some 1X2s to frame out the window. Sounds good until I read the window should really overlap the upper frame by a couple of inches. Much to my dismay I was able to break off the 1X2 with minimal damage to the plywood.
Next I decided the 1/4 inch plywood would not be strong enough to seal the window against the wedges so I glued up some additional 1/2 boards around the frame.
Once that was done I knew I needed to make an angled window seal. I used 1/2 wood for this and hand planed a 25 is degree angle.