End-of-Month Update for July 2021: I decided to start some work on a practical project, a steam boiler for my workshop.  Design work alone is going to take quite some time, and I have no idea when I'll finally get round to building it.  Depending on how much the raw material costs, and what my income is like when the project finally gets going, I may add another funding goal here.  So far, I have two entries for this project, part 1 and part 2.  Follow me on Hive for more updates.