My '82 has a classic issue: someone in the eighties cut holes in the door panels for speakers. I've a red interior and the panels are otherwise in okay shape. Anyone tried, well, patching? With something? Worked out? Dumb idea?

Would look more natural if you cover it up with a speaker grill, perhaps with working speaker beneath it, at least it would be functional.

You'll never patch it so it can't be seen. If Arik's idea of putting a speaker grill on it isn't appealing another strategy would be to cover a thin piece of plywood with an accent color and cover the hole with that. That way it's covered but you're not trying to match color and make a giant hole look invisible.

A thin varnished wood panel to match the dash could also be applied to cover the hole and possibly be elongated into a accent strip going the length of the door similar to the metal kick plates.

You can get quite artsy fartsy with this if you think beyond the dimensions of the speaker whole left in the door panel.