Interpretation of 1911 GB parish data

The 1911 Great Britain NAPP data comes at the level of parish (variable parishgb_1911), which runs from 100001 to 111530 and then 999999. I am looking for a map to match these parishes to. Centroid coordinates of parishes would help, as would a shapefile. Names to these parishes may also help me to match them.

One thing I am aware of, seems to be a dead end: I found a UK 1911 parish map here: visionofbritain.org.uk, but indicators on this shape file do not match with the codes in the NAPP data.

Many thanks and best wishes.

The PARISHGB_1911 variable is actually part of the Integrated Census Microdata Project from the University of Essex and reflects their consistent parish coding system found here. As the documentation describes, these codes were created in conjunction with a GIS project. I was not able to check the actual boundary files myself, but it appears as though they should be available to researchers. See this article for more information.