Language in historical novels - Paradiso, Paradìxo, Paradise

Language in historical novels.

What possessed me to include Italian language dialogue in my novel? Authenticity? A fascination with language? Embedding the story in a culture other than my own? 

All true and manageable until I realised that the characters would not have spoken Italian but Venetian in 1879/80. More to the point they would have spoken a regional dialect of Venetian. How was I to respond to that challenge?

Three ways
1. I discovered an Italian/Venetian/English dictionary on-line which I used to do a rough version.
2. I asked Claire Kennedy and the Brisbane Dante Alighieri Society for assistance.
3. I sent a call for help to Marina Battistuzzi in Orsago (my great g'mothers village) in Veneto, Italy (I first met Marina in 1988 - a remarkable tale of three meetings over 28 years). Marina informed me that Orsago and the surrounding villages speak a Trevigiano dialect (Treviso is the capital of this province) rather than a Venice based dialect. She offered to help.Today I received back six pages of translation and notes from her (I had sent her a cut and past version of all the Venetian passages in the novel - more than she expected I suspect). 

There are some subtle differences: papa is Italian pupa is Trevigiano; thank-you is gràsie not grazie; Paradiso is Paradìxo etc Some words have clear roots common to English 'commode' is 'còmoda' for example and some words are spelt quite differently. Imbecile is 'inbezhilàt' in Trevigiano and 'imbecille' in Italian etc etc.I also discovered that the Italians and Venetians have a fabulous range of insults in their languages.

It has been a rewarding but tedious word by word process.