Thanks again g-force and dark_jedi. It wasn't the Avisynth version (although I am now using the one you posted), but it was a few filters that needed older versions to work. I had two or three filters which were newer versions, so I reverted to all the same versions as included in dark_jedi's post.

I did some testing of short clips throughout the film to adjust the settings a bit and now I'm running my first full encode to Lagarith.

If it works out, I'll encode with HCenc, then I'll just have to decide which audio to use. I think I'll start out with the Belbucus DC48 audio, then maybe I will try hairy_hen and Satanika's 5.1 upmix. I was thinking about trying my own upmix with the unedited DC48 and hairy_hen's LFE, but I'll have to do some more reading and testing to see if I can replicate Satanika's process.