the translation for strozzapreti is correct...
Norcino is the word used to indicate someone that practice an ancient "art" ,typical of Norcia, ( the name of a town ) of making sausages and hams. Norcineria is the name of this art.
Hoping it can help, and it' s the right interpretation
Strozzapreti is a tipical meal so called because considered rich of ingrediants and particolary tasty that even the priest of the village could not resist to refuse it. But he has to eat it till he dies.
This name has to be placed into general anticlerical attitude of part of population during XIX century.
About NORCINO more than for black Norcia's truffle, it has an insulting meaning (see demauro Dictio) the main activity in Norcia at Middle age was the cattle castration and because of that the Norcino man was always dirty and vulgar. It' s a qualification of incompetent surgeon.