For me portholes are not that important on small vessels as long as they look OK, but nice to haves, rivets never look right. Of late I've done some scratchbuildiing and salvage. Relying on photos I'd probably add details like this and have counted between deck stanchions, although +/-1 is my specification.

I have high hopes that as 3D printing improves realistic barely preceptible rivets will be possible. If a human crew member isn't easy to achieve then a rivet is invisible at a couple of microns?