Hello Larry
I used card with the rivets punched through with a sharpish point….and then glue the card onto the hull…..for a very pleasing effect.
To add rivet heads to a plastic hull is very easy!……….Use PVA glue and a hypodermic syringe!
You will need to practice first to get the right size of rivet.
I think that pin heads would also be ok……..Just knock pins in and snip them off on the inside and with a coat of paint to seal them…….Job`s a good `un!
Bob