skidoo I carefully read through your post here today, yesterday I went through it like a starving pygmy at a buffet table! Excellent!
I see a bit of "HLA" inspired ideas. I think you lost
nothing with your 167* wing rotation, and your design oversight with the cyl. clearance was beautifully disguised with your solution and I think may have added some (possibly) needed support along the hinge section. I hope you are a fabricator at a big time shop during the day, your build is giving me serious feelings of inadequacy.
I plow driveways with a tractor that has a Fisher 9'6" V (frame mounted), and wanted something to pull snow away from doors (think simple box blade). My wish list was to be 1- heavy to keep me in 2WD most of the time. 2- to be "close in" to the tractor to keep the overall plow/tractor length down. 3- the ability to carry some snow on "reverse trips" while win rowing some of the bigger lots. (Church size, not wal mart)
After failing to come up with the linkage required for a 180* wing I wimped out and am just going with a more normal "box pusher" design that will be able to mount to a detachable 3 pt.hitch from both sides via a "eruo/global" type hitch from both sides for a real pusher box when wings back, and a good snow carrier for doorways when wings forward. On my "route" I will only need to switch it 1 or 2 times.
Did you ever check into those "rotary actuators"?
https://www.helac.com/products/rotary-actuators/
they look too expensive for me to even inquire.