quilt938,
The crinkle finish is quite durable and was popular with the manufacturers back in the 40s and 50s. Not so much with the consumers I've been told. I like them. They are easy to keep clean and are less prone to scratches and nicks. Not to say they are impervious to such damage, just a bit more resistant to it.
The crinkle machines are exactly the same thing as the shiny ones, so forget the emotional factor and sew with it. I have two 66-18 crinkles and they both sew most excellently.
Some crinkled Singers were remanufactured machines with the crinkle paint applied over the original paint. Others are OEM Singer. The factory ones have a much better appearance.
The black side parts can be hit or miss. Some of my machines have a piece here or a piece there, but none of them are completely done that way. I have no idea why.
Joe