John E.
I am new to this forum, but I agree with the others here; you are being too hard on yourself. There are two critical lessons one must learn when doing something artistic. First, nothing will be perfect and second, when it is time to stop and move on to the next part of the project. Most people pick up on the first one quickly, but the second one is a lot tougher to learn.
Over the years I have done model and high power rocketry, oil painting, watercolor, scale modeling, wooden ship models, photography, stained glass, woodworking and even some writing. I am a mathematician/engineer by profession so I can be a little obsessed with getting stuff right, but most of my hobbies have taught me to learn to put the paint brush, pen or glue down at a certain point and declare a project is done. The same thing applies to individual steps in a project. I could keep pouring time and effort into a particular part, but I really won't improve it significantly for the time spent. I have learned to accept that it won't be perfect, but it will be good enough.
I have a stained glass project that amazes everyone who sees it. Most of the mistakes I made in that project I have long since forgotten, but some I notice every time I look at it. I don't let it bother me; I appreciate it for what it is.
Even if you decide your ship isn't great I urge you to keep it around. We all learn from our mistakes and keeping your bireme around will help you remember things that didn't go quite as you planned and maybe try something different the next time. And it will give you a great reference point when you complete your next project. You can look at your bireme and see how much you have improved.