Awesome, I had planned on doing this myself.
I am designing all the details for a full reveal. I like the full shape of your "reveal" attempt (last in pictures), but where it connects to the neck portion, it should look like how you have it for the first photos. (Where the tusks join in, there should be a triangle that remains attached to the lower neck/chin part)
Anyhow, I might attempt to poke holes and make it a screen accurate reveal, inside and out. I am building the Geoffro reveal I paid for, but its not 100% RPF accurate.