While looking for retro/steampunk keyboards on Amazon, I found two exceptional keyboards. No, I will not be buying a 12 pound $1600 keyboard in my lifetime.

Seafarer Keyboard

I first thought the next one was a real typewriter with USB but it is only a keyboard with two large scroll wheels. I am not sure what the lever does. Maybe send carriage return and linefeed. It is wireless so not useful for this project.

https://www.amazon.com/Qwerkywriter-Typewriter-Inspired-Mechanical-Wireless/dp/B01KM6EJOY

There are a few more reasonable priced retro keyboards with round key caps like old mechanical keyboards. No retro thermal printers though.