Originally Posted by Bigtalljv
yep. Pretty sure I saw a picture somewhere with a gun mount stuck in those.
My light bar/arch fits in the two holes for storage on my Willard (Pic #1/#2). I've always seen the .50 caliber mount attached the the sampson post (Pic #3). Also in pic #3, you can see the edge of the arch in it's storage spot (I had only seen that in pictures of older Zodiac though).
If you ever have a chance to just cruise through pictures, go to Wikimedia Commons
and search "rhib".