How can I repair or hide dings and scratches on polyurethaned trim?
If it were me I'd hit it with a dye stain first to help color the scratches but this takes a light touch and a bit of experimenting to get the tone right. If the marks disappear with a little oil you can probably just apply (after a good cleaning with Murphy's Oil Soap) a light coat of linseed or tung oil, followed by a reapplication of whatever poly was originally applied (the brand isn't often important but you'll need to know if the finish was water-bourne or oil based) or spot treat with a good wiping poly if you don't want to do the whole surface again. Another way to go about it is to accentuate the defects and call it distressing. If you like the worn look, substitute the oil with a quality glaze in the Van Dyke brown family, we like Sherwin Williams solvent based glaze. With all of these techniques you should do a test on an inconspicuous area to check the look and compatibility. Good luck!