Picked up a Tower Commander Portable at the local flea market Saturday, and while it's in fairly good shape, it has a major issue with the right-hand margin stop and line lock.  I found out that it was sold by Sears and built by Smith-Corona, but I'm not sure the mechanics for the margin stop are the same.  I think the machine might have had the carriage hit by something because the stops look pretty bent up.  Anyone have one of these?  Is this a common problem? 
Thanks
P.S. haven"t had a chance to set up a photo site yet; sorry I have no photos.