Sealing between transom housnig (gimbal) and hull - caulk or cork?

I need to reinstall the transom (gimbal) housing for the sterndrive (SternPowr model 103). On initial installation I could not find original gasket, which was made of something like rubber or cork-rubber so I have used only caulk sealant (Sika 291 UV) which worked OK for 3 years and probably would work more if I did not have to disassemble the housing for some service. When disassembling, I have unglued a couple of layers of fiberglass. Now I have fixed that, but thinking of going different sealing route on re-installation. So here is the question:

What is preferred sealing method in this case?

Here is stuff available in my location:
1. Polyurethane caulk (Sika 291 UV) - bad experience on disassembly, but otherwise works
2. RTV silicone, i.e. Permatex Ultra black or similar from Loctite, I have used that between upper
and lower case of sterndrive with good success (instead of gasket).
3. Cork gasket - I can buy a roll of cork and cut it in shape I need - is this reliable for the application?
4. Cork mixed with rubber, but unknown rubber type - same scenario and question as described in 3
5. I have read somewhere on the internet that people even use 3M wheatherstrips, that could be
found here, but is that really reliable for this application?

Thank you in advance for your answers!

 

I hoped that someone with experience will give at least some answer.

I have decided to use cork mixed with rubber as a gasket, so we shall see how it will turn out (4mm thick, cut to shape). I used scissors and utility knife with metallic ruler for cutting, but be careful with ruler on which side of drawn line you put it so if it runs away from ruler it cuts dead side rather than gasket side. Knife must be used at least twice on the cut line to cut through thick material. Assembling it was very easy and it can be good compressed to eat some uneven surfaces (uneven surfaces were rather on aluminum near bolts than on fiberglass, corrosion due to integrated stainless bolts in aluminum body).