[wwb]

....... what would be your advice?

Dead serious.... put the rail & red dot back on it, and sell it to a total stranger you hope to never see again. If you can do it without taking a financial beating on it, so much the better, and consider it a cheap lesson.

A very simple rule to live by: If it isn't the way it came from the factory, walk away from it. Far too many guns with so-called "professional" work have been nearly ruined, and most with true amateur work are basket cases.