To close small gaps at work, for varnished work, we dab a little wood glue on the gap and sand the area with 120 g. The dust and glue disappear the spot and the match is perfect. Note, "work" is 90 foot plus wooden luxury yachts. Just to bring it back on topic I do have a gunstock clamped in my vice there, a box of small parts and a barrel on my bench, in the shadow of a 55 foot Trumpy no less. Needs must when the devil drives.