I'll agree on some of that i.e. no large scale production of synthetics, no mass produced transistors and very significant supply chain issues. This will result in odd pockets of technology fallback. But that isn't the end of our know how and you can accomplish a lot with cruder solutions. In fact the scenario you are examining will actually force a planned drop to a sustainable tech level that would allow a gradual build back to the world we know today. To that end, vacuum tubes would be pretty easy to build if you have the knowledge and access to some rather low tech capabilities. Crude transistors can be built with material in a high school chem lab. Machine tools and the skills to use them will be worth much more than there weight in gold.

I would expect to see electricity (including local power grids), steam power, and internal combustion engines available in lots of communities. In terms of agriculture, if the fall back goes past early tractors (think steel wheels or treads, not rubber) it will probably go all the way back to human power. It takes a long time to raise and train draft/plow animals and that know how is already pretty rare before the apocalypse. Any draft/riding animals will be very hard to come by even 40 years later. Unless you have a tannery and a black smith near by tack and other gear will be pretty crude. Similar story for wood working - not a lot of human powered wood working tools out there these days so we better hope for some grid power.

In preparing your character maybe consider some training as a naturalist / herbalist. Our current medical standard of care relies a lot on big companies and dependable transportation that will break down. Some basic knowledge of herbal medicine will go along way in a world that doesn't have easy access to tylenol etc.

Good luck and have fun,

- Eric