Glad the pictures are of some use. Note that there is a black seal that goes all the way around the rim of the bottom half of the toilet -- it seals the gap between the top and bottom halves pictured above, and the seal is not shown in the pictures. If you don't see it when you pull off the top half, look underneath the top half as it is probably just caught there. Be VERY careful when you seat this seal during reassembly. After you seat the seal, slide the top half onto the bottom half and DO NOT lift it back up unless you plan on inspecting the entire seal again before letting it back down. I didn't do this the last time, and the seal was dislodged during reassembly, and I had some leakage there.
Wayne (harveyrv) - Glad to see someone noticed my legs. I work hard to keep them in such tip-top shape.
Good suggestion about attaching some cleats to hold down the screen. I'll try to find out what the toilet is made from.
Roy - I was having problems with solids flushing last year as well...before I installed a brand new skirt. It seemed to get a bit better after the new one, but now the flushing action is back in the crapper (pun intended). I cannot imagine that the skirt would dry out after such a short time, and it certainly doesn't feel dried out. Maybe the skirt just needs to be finessed occasionally, as my 9-month old skirt has now put us back to where we started.
Dave