For some reason the original owner of the house omitted a good 2" section of moulding from a wall panel in a dining room - and I couldn't find a place that sold the same type of trim. To make things worse, the margins were cut at a 45 degree angle like they were intended to be mitered, but instead were just left unconnected to anything.

I traced the moulding edge and then de-skewed it from (what I assumed to be) the 45 degree cut, then modeled it & printed it out with PET-G. I drilled two small holes for nails to be driven through it, then sanded the print with lightweight spackle. Once it was on the wall it was primed & painted. PET-G doesn't take paint super well, but the low-poly print and sanding with spackle did the trick well enough.

I give it a resounding “meh, at least it's better than before.”

Submitted just in case this is a helpful template for other home projects.