I went through three 50mL MA300 glue packages today. I bought a more expensive metal dispenser ($25) and I am sure it was a good choice. So I did my grooves with a Foredom flex shaft tool. Way more comfortable then trying to use the Dremel. I have done quite a bit of work in the past with the Dremel but I picked up the Foredom tool very cheap at a garage sale. It has more power at lower RPM. It is better to run lower RPM as you do not generate as much heat and it cuts faster. Yes I tried the Dremel tool also to see which one was best. Hands down the Foredom tool. More control on where you cut, no heat on your hands, and way more power. I have included some picts of the glued parts. This is the first step and I am not finished. I still have some more at the rear to do a first fill and I will add some to the other joints as a filler. I will also cut down a couple of the longer lines and add in a layer of glass. As expected the MA300 had a solvent action on the plastic. After I layed my initial line of glue I worked it into the crack with a small spreader. The thickness of the glue caused it to pull at the surface and that is why it is concave when done. I do not know how much is also caused by shrinkage. I expected this from some of the body work I have done in the restoration of my 1931 Model A Ford Cabriolet. I found the slightly larger then 1/8" holes I used as crack stop were a good fit for the tip of the glue. I drilled a few extra holes where I knew I had a slight plastic separation near the crack. I pumped some in the hole. I did not do much as you have to be careful with the heat generated. I found those areas got pretty hot. The screw holes were kept open by screwing in the screw and shortly after applying the glue I removed the screw and cleaned them. I used denatured alcohol for cleaning. I used blue painters tape to limit my sanding. I masked off close to the edge on most the places. Before the glue set hard I pulled the tape off. Next, wait for more glue to show up. I also need to make up some flat boards for gluing down the floor areas that have pulled loose from the foam. I will be following Dave's recommendations and using the gorilla glue. In picture PA080273 that is one of the longer ones that is likely to get glass. That one was odd. Up over the side the crack had a bit of separation. Down on the floor where the crack ended it was overlapped slightly. So the shift in the structure pulled it together down there. Of course, the shape is very complex through there so there would be a lot of forces.