Thanks! I did locate a free online manual for the 500A and 503 and they both give attention to applique so this machine may complete my trifecta (then when I win the lottery I can collect more machines and also buy the bigger house I will need for them

)
The 500A manual does show lots of examples of Applique, though the basic stitches do seem to be the same as the 503 (
http://www.sew-classic.com/uploads/S...500_part_B.pdf). The 503 doesn't show as many applique examples, but does mention free-motion (
http://www.ismacs.net/singer_sewing_...ine-manual.pdf). I understand neither machine is great for FMQ, but what about FM applique?
I'm still having trouble discerning whether they are truly comparable in terms of number of types of stitches. Does the 500A with it's built-in stitches plus cams end up with more overall, or does being able to use cams + the 400/403 model cams basically even it out?