SQ - Assumption Multi-Cache

The SQ in the cache name above signifies Spirit Quest, a project to distinguish those caches that are set in cemeteries or memorial gardens. Please be respectful of the area, and observe their rules and posted hours. This is a two-stage multi-cache. The posted coordinates will bring you an old mausoleum located in the center of historic Assumption Cemetery. Some graves at this cemetery can be traced back as far as 1795!

Using the letters of the family name which adorns this mausoleum, and the following substitution cipher, A=1, B=2 ... Z=26, solve the following to reveal the coordinates for next (final) stage:
North 42 18X
West 083 0Y
where,
X = 190 + (first letter) - (second letter)
Y = 4024 - (sum of all letters) - (fourth letter)

PLEASE REPLACE CACHE AS FOUND.

++ Congratulations to skidsavage on the FTF!! ++