In checking out the sled in greater detail, I found that the black Philips-head screws that are used to secure the lower plastic panes(below the removable side panels) were very tight-had to resort to a screw extractor for two of them.
If you remove the screws, be sure to have a good tip on the screwdriver-I did and still had problems. Maybe a Hex(Allen) head fastener would be used in place of the oem.