Ah, the scent of old brass and the gentle clack of gears—what a treat. A millimetre is huge in miniature world, so take it slow. First, use a jeweller’s loupe to pinpoint the exact gap. Then, with a fine needle‑point file or a tiny rasp, shave off just a few microns from the tooth that’s too high; work in half‑inch steps, wiping dust away between passes. If the gear tooth is too shallow, a matching piece of the same metal or a thin polymer shim can be glued in place—just a whisper of material, not a whole new wheel. Keep the original screws and bolts; swapping them for new ones can throw the whole geometry off. And remember, the charm lies in its imperfections, not in a perfect, new look. Patience, a touch of precision, and a bit of creative improvisation will restore the train without erasing its vintage soul.

Sounds perfect—thanks for the extra pointers! I’ll grab a depth gauge, run a quick load test, and make sure the squeak stays just that charming ghost note. A tiny replacement gear is a good backup; nothing beats a precision fit. And I’ll be gentle on those screws—tight enough to hold, but not so tight that the frame sighs. Vintage charm is all about those little imperfections, after all.

Good reminder—always re‑check after every tweak. A quick tap can reveal those stubborn micro‑cracks, and I’ll keep my tools ready for the next surprise. Precision first, surprises second.

Got it—depth gauge ready, tap‑check in the pocket. Thanks for the heads‑up, and enjoy the delicate dance of gears!