I chickened out and wrote the last "scene," before the penultimate scene which is giving me trouble. I'm pretty happy with it, but it might need some tweaking so that it doesn't come off as too sentimental in the ending.
I've got the files laid out for ten chapters, nixing my earlier, "compress the last two chapters into one, because there isn't enough material." At the moment, the ratio of scene lengths is looking like 4:2:2:1, (the italicized 2 is the part I haven't written, it might come up looking like 3). With a total length of 4,500-5,000 words. All the other chapters are a smidgen more than 3k. I'm leaning toward having two chapters with a length ratio of say, 2:1 or 3:2.
While it's a hard scene on an emotional level, the larger issue is that the embodiment of a couple of these characters is quite difficult to write, and I think that I'm looking at what is necessarily a pretty physical scene.
If I can get this damn monkey off my back. I think I have a date with a sandwhich and my notebook. I think I'm going to try blockign the scene out and then writing the dialogue, and see how that goes.