Ok. I've seen mention of the limited amount of O Scale 2 rail Rivarossi AHM Plastic locos that were made in the 60's and 70's. I recently procured a dilemma locomotive. It's a 2-8-8-0 N1-sd for the Reading #1827.
It's definitely Rivarossi for AHM. It needs some repair in the front end broken step in the front and some of the cylinder tubing is missing.