John -- there seem to be eight items in the John Davis White collection on the TCD website emanating from John Troy. Each has a differently worded imprint, but four them locate him in Waterford, as follows:

A lamentation, for the Pandora. Which was lost, last week off Youghal
John, Troy. Printer, and wood; Engraver

The peddigree of Alias McCarthy, the Irish fugitive, who was exiled after the reign of King James
John Troy Printer Stephen Street, waterford

The lovely Irish maid
John Troy. Printer 40 Stephen-St. Waterford

The Indians' war
John Troy Printer Waterford

The young sick lover
John, Troy. Printer, and Wood Engraver;

A new song on the arrest of Thomas F. Meagher, Esq
John Troy's Printing Office Stephen-Street Waterford.

The breeze
JOHN TROY. Printer and Brass Engraver

A new hunting song
John Troy's Printing Office