I adore the `Threaded Interpretive Languages` book! It very clearly describes the internals of a real language, and variations on how to get it all done.
Yes, it's a lovely book and led me to my first paid project over 40 years ago! Using the book I built a Forth to monitor the local water authority systems, with water-level tracking and customer accounting & billing, implemented on a home-brewed network of North Star PCs. Iirc there's a minor bug in one of the base subroutines as written though now I don't remember what it was. But I still have the book :-)
https://archive.org/details/R.G.LoeligerThreadedInterpretive...