Sew, it's working much more naturally, as in it tends to sew straight lines.
After a shot of bourbon and a good hard think, a little grease and different placement of a locking washer I am getting a much cleaner and softer sound from the machine. It is going to be fun over the next several months getting reacquainted with the original setup of my 1911 Singer 66. I hadn't really become accustomed to the side clamp and revco modification, but the fact that I could use more attachments and backtack felt great! I guess my 201 will have to suffice.
Here is a YouTube video showing the REVCO stitch regulator, it really was nice using my 66 more often. But, most recently I've been using my 201 more because I haven't performed any modification to it. So I think that tells me that I'll be happy restoring my 66 to its original back clamp, forward only state.