just rereading your 1st post and yes, the mast rotator goes between the diamond wire tang rivets, IF, you've got the space

from your 1st pic it looks like you have a lot of mast rake, your main sheet blocks are very close

perhaps that threaded adjuster was added to allow for more mast rake and to make it easier to adjust

or it may have been added because the forestay that is fitted is too short

removing it will pull your mast back up to vertical, make sure it doesn't start leaning forward

i haven't experimented with mast rake on my 5.2 yet as according this this page

http://users.tpg.com.au/kkmiller/hobie/weather_helm.html

it increases weather helm and my boat seems to have just enough as the mast is now

also i'm only sailing solo and have to move forward to the dagger boards to try and balance the boat in light winds

for me more mast rake would increase weather helm, move the center of gravity and the center of effort back, something that i don't want at the moment, (comments from the pros welcome)

however as you are an experienced sailor going out with 2 or 3 people in probably heavier air, that amount of mast rake may be perfect

final comment, 1st pic seems to show an extra inspection port in the middle of the hulls

does it look like it was added after the factory?