I use my #57 alot also. Instead of the moleskin, try a small stack of post-it notes with the tacky edge at 1/4". When they no longer stick, just tear of the bottom one (write a note) and restick to the machine.
I think the moleskin eventually gets an indent, which throws off the 1/4". Experienced this with the 4H kids who needed a guide.
I agree not to use generic feet on any machine. Why go to the expense of a good machine and then "cheap it" on the feet. My "Lucy" would not be happy with me if I tried it.
I also agree on using the single hole needle plate. What a difference in piecing!