I have yet to see once of these ships with perfect (relatively speaking) saucer section seams. I think it's the nature of the model. I have a next generation Enterprise, it's huge, made of plastic, and the saucer section seams were off on that too. Maybe different heat from different mold times, I don't know. I think if the inside section of the edge is doubled up, and the inner section is one thickness smaller than the side, it may lead to the journey of seams.
I recently 3D printed 2 F-22 models from different people. Both got the jet intakes wrong, and gluing sections meant holding the model in my hands, tweaking it while it dried to finally get a ho-hum fit. Some sanding, filler, those models took about 5 hrs. each to print. Talk about let down. The models I get off the web from "Thingverse" and "Makerworld" aren't very good so far. They're are O.K., but will take much work to paint and detail, as they are all one color..
Making things require due diligence, and sometimes the nature of the beast just comes up to bite you in the A$$. It's good that we enjoy doing this, and that in the end, the sum of the parts make for a great model. This model, if I didn't know better, I would think was greebled, I can imagine, if you do it again and greeble it, how much more intense it would be. This is my favorite Star Trek star ship. Great job.