I may have posted this before, but here are pictures of the generator[1] and furnace[2].

As a bonus, I completely forgot to mention my homebrew ethanol still[3]. I applied for a small fuel producers license from the ATF/TTB which required me to denature it so it could only be used for fuel purposes.

[1] https://chrisbergeron.com/2008/08/24/homebrew_generator/

[2] https://chrisbergeron.com/2008/01/21/metalcasting_furnace/

[3] https://chrisbergeron.com/2007/08/07/ethanol_still/

Small motors have a variety of uses in this kind of scenario, fuel limited of course. They can provide electric power, but also power your mills and other machinery. They're also (relatively) easy to maintain and repair, not a skill everyone has, but a skill nearly everyone can learn.

Of course, since it is fuel limited you'd want watermills and windmills, along with other manual (human or animal) powered systems, for driving machinery most of the time. Now, if you can get a diesel system going then you have the possibility of using biodiesel which would alleviate some parts of the fuel problem, assuming you have a source to produce the biofuels from.