RE: Aristocraft manual switch machines
Welcome to the forum,
How about an over-center spring? Simple and reliable with few moving parts. I believe Totalwrecker had a topic on them recently. Ah, Here it is. Not sure about the specifics of posting links but the topic is 'Low Tech, backsaving, semi-automatic manual switch machine' and can be found in the Track, Trestles, Bridges and Roadbed section. It's about ten posts down at the moment. All you need is a piece of spring wire and there are pictures that show everything. I do not have any experience with Aristocraft switches but I prefer the springs over LGB's manual throw which often were too weak to throw completely. Just push the points over and they stay.