Pictures would be an asset however from your description I agree with Looky assessment of $850. They are a nice little rifle and are in demand. Many folks ask 1k +++ on the EE, who knows what they actually get. But I would say depending on condition price it in the 800 range and it will sell, with fairness to both parties.
I have one with a Hollo sight on it and will take it to my grave, great light handy bush gun, plus I have never had an issue with it functioning. If you flip the gun upside down and look at the loading port there should be a little round button on the right inside which is a cartridge cut off to aid in unloading the rifle without cycling all the cartridges through the action. If it has one that's a bonus if it doesn't it means it is one of the earlier models. I am not sure what year they started putting them on. Also the older models have aluminum butt plates as opposed to the newer ones having plastic. I have never heard or seen one with a monty carlo stock, in traditional Ruger style there usually plain Jane walnut, and rather beefy and pround to the metal. Hope this helps.