23' Transom Advice Request

[Water Rat]

I am hoping to tap into the considerable talent of the membership here and thank you in advance to anyone responding. I have a 1978 23' Sceptre I/O (some pictures are in the gallery section under "Chris Downey's 23 Sceptre" (thanks to Trayder) which finally needs a new transom. I am kicking myself that I did not recognize this last fall before I winterized the boat and could have had the work done over the off-season, duh.

I'm seeking input/advice from those in the know on this site. Thanks to the incredible contributions many have made here over the years, I've become something of an "armchair" mechanic/restorer but will have to have the work done professionally due to lack of time and skills (though will attempt to do what I can without screwing it up or getting in the way).

My thought on the right way to do this is from the inside of the transom vs. outside. I am de-rigging the transom and having the engine block pulled now. My thoughts are to do the following for the actual transom replacement:
1. remove interior fiberglass skin, leaving a "lip",or flange around the perimeter approx. 3"
2. remove/grind out the existing core (rotten plywood) and prep the surfaces (degrease/
clean/grind/sand)
3. replace core with Coosa Bluewater 26 panels instead of marine plywood
4. have the whole job performed with epoxy vs. polyester or vinylester
5. I have no real idea of what type of glass or lay-up schedule should be used
5. by having the replacement done from the interior, I am assuming a stronger transom
repair can be achieved by being able to "wrap" the new glass forward on the interior
hullsides, bottom and stringers - a side benefit would be relatively little fairing and
cosmetic work at the end of the process compared to doing this from the outside

One question for those that have done a 23' transom from the inside, is there enough room between the transom and the aft bulkhead of the cockpit liner (approx. 16") to allow this to be done? Also, to allow access, could the gunwale/cap be cut just forward of the hawse pipes for the stern cleats and removed from the stern area to allow better access and working room, then be re-installed and the cut re-glassed and faired with no loss of strength to the cap?

My goals are to have the job done right, with the best materials for the application, and to make it as strong as possible; while the boat will remain I/O for now, there is the possibility of converting to bracketed outboards in the future. I'm sure there is a lot I'm missing and again, thanks in advance for any input here.

Thank you,
Chris