Patrick, I’m working in the same area as you are. 

Q1: I have a 2003, and the mast and compression post are offset as you describe. I’m considering making a compression post that extends to under the mast. 

Q2: I don’t follow what you say about the notch. Look at my post from earlier today, and they are three pieces of wood that form a box partially filled with concrete to support the compression post. The center piece in is immediately under the compression post but wasn’t mounted correctly (too low) to support the weight of the mast. With no support under the compression post, the plywood decking sagged and started cracking. There needs to be support under the compression post. The OSB (!) wood in my support is not treated in any way.  

Sent from my iPhone

> On Mar 6, 2021, at 4:08 PM, Patrick Cheung <chitakcheung at gmail.com> wrote:
> 
> ?Dear Rhodies,
> 
> I am seeking advice from you all.
> 
> The compression post is sinking approximately half an inch. I removed both
> floors in the main cabin and in the head area. Both plywood floors clearly
> sagged with the weight of mast and compression post resting on it. Sitting
> at the companion way one day, and staring at the mast and compression post,
> I noticed they don't line up, the compression post is about 2 inches to the
> starboard.
> 
> Question 1: Does your mast and compression post line up?
> 
> Question 2: Compression post is notched, 2/3 sitting on the head floor, 1/3
> sitting on the main floor, and there's no support immediately under the
> compression post. Is it advisable to add support under the compression
> post, all the way down to the hull?
> 
> Since I own the boat, the shrouds are always hand tightened.
> 
> Thank you in advance for your advice,
> 
> Chi Tak,
> Duck
> Lake Simcoe, Ontario