“he used no metal hardware or nails supposedly, must have had some really good glue.”
....early furniture makers used pegs....in some applications the secret was to peg together semi-cured wood with a seasoned dowel...as the wood dried it would shrink up tight against the peg....timber framers did the same thing....I’ve got a cabinet that’s been in our family for over 200 years...not a nail or screw in it.
You should drag your cabinet to the next Antique Roadshow in your area. :-)
I marvel at the inlaid work that was done as well.