Try contacting Ken Loh. He is Grand Banks parts manager in Singapore. I believe his email is kloh@gb.com. If that email doesn't work then you might search the archives at Grand Banks Owner's Resources.
I recently heard that replacement boat plates can be ordered through Grand Banks. Good luck!
Yes, I can custom make the ID plate for you. See photo attached as sample. It will cost you $ 45.00 a piece. Lead time is 3 to 4 weeks.
Please feel free to contact me if you need my further assistance. I am happy to help. Have a nice day ahead.