sealing my replacement lewmar hatches

[YPSILANTI]

I am in the process of replacing my Lewmar hatches. I live in South Africa and our Rand US Dollar exchange rate is 16 to 1 Dollar. The imported components are thus prohibitively expensive. We thus need to be resourceful. I have sourced and had the hatches laser cut from Cast Acrylic as per the advice on the forums. My questions are as follows:
1. Do I have to buy the rubber seals from Lewmar or can I seal the new hatches into the frames without their rubber seals?
2. Research suggests that I should seal using VHB 3M tape and then Sika flex 295 UV with the primer & GE SG-4000. My concern is that the tape will be inside the frame and as the hatch touches the frame, it will catch and bond without being able to be correctly positioned and seated. If I can indeed proceed without the Lewmar rubber seals, should I thus not exclude the tape and only use the Primer and Sika?
3. We can only source 5mm tinted acrylic which is too thin. I require the 10 mm which is clear and is not available locally tinted. I am thus considering having a tint film that is sourced from the USA that is applied internally sits well without an adherent? Has anyone done that?

Any advise, referrals or useful links will be appreciated. Thank you. Regards Mike