I'm sure there are multiple uses for the carriage release by-passing the right margin, but personally I like just being able to move the carriage without having to use the margin release key. I should check the SG1 manual and see if there's something specific written about it. To double check your margin position you can always let go of the carriage release when you hear the margin bell and use the space a few times.

There are actually three positions to those swtiches. I and II adjust the distance of the plastic line indicators from the platen. In the third position it pops the indicator forward, well off the platen, so you can clean the backside of it. 

It is extremely common for the brackets that move these plastic guides to have detached themselves, so if yours aren't doing what I described you'll need to remove the carriage and pop them back into place.

Any recommendations on a cover for the SG1? Some of the ones that I have seen online don't seem to have the best dimensions. I had an original Olympia one...but someone in the house here mistook it for a plastic bag and got rid of it  

Ektagraphic wrote:

Any recommendations on a cover for the SG1?  

No, but it's a very good question. At some point I'm going to begin using them as they do collect dust, and the one thing I hate more than spending hours cleaning a typewriter is having to clean one that I've already spent hours cleaning. I would think that most covers meant for a standard machine would work, providing you don't have a wide carriage on your SG1. I have a few new covers (don't know which models they were meant for) that are still in their original packages that I keep meaning to try, and one SG1 with an original Olympia cover on it. Would the dimensions from that help you?
 

This website has them, and others seem to have generic plastic ones, but all would be too small for the SG1. 

http://www.vintagetypewritershoppe.com/catalog/item/3814274/9378108.htm