That "just for show" mindset bit me too, same deal with a loose cannon plug but on a 1900. Chased a fuel gauge fault for two days, turned out the plug behind the panel was half a turn loose. Now I torque seal anything that can vibrate, cannon plugs, B-nuts, the little screws on relay panels nobody ever pulls. Pro tip, put a small stripe across the nut and the boss, not a blob. Blob hides a loose fastener if it breaks the seal clean and you are not looking close. Also write the date on it, takes two seconds and tells the next guy when it was last touched. Cheap insurance for a Saturday.

You said you can't see it unless you shine a light at the exact angle, and that's been my experience too. I did a similar 45 on a corner seam last spring and after I hit it with the polishing pads, my own customer couldn't find it even when I pointed right at it. The trick for me was to make sure the glue was fully cured before I even touched the sanding, rushing that part always leaves a faint line. People get way too scared of seams, but if you take your time and match the grain direction, it's a solid fix. I'd rather do a clean seam than tell a homeowner they need to drop another four bills on a whole new slab.