Hi Tom;
I spent my time in Ripton and Middlebury, also mid-state.
The Wisner's book is excellent; it will give you a solid background in
RMH information.
However, it will only tell you about J-Tube construction and piped masses.
RMH technology has moved on.
Most new builds are now Batchboxes utilizing a brick bell. (Stratification chamber)
Easier to build with significantly less labor than making
cob.
You can learn quite a bit simply by reading threads in the
Rocket Mass Heater forum.
I also offer
books for sale.
You might be interested in my Batchbox core construction book, which is available at
https://dragontechrmh.com/
There are folks in New England who have RMHs; perhaps one will reply who lives nearby you.