I don't know who took what plans where, but I do think this site has a lot of useful Inglis info:
http://ai4fr.com/main/page_militaria__collectibles_canada_inglis.html
I do know that I would not recommend refinishing an Inglis, regardless of its value. There is something about holding an original military firearm (or any other piece of history) in its original condition that fascinates me. Perhaps you should sell that one and get a beater commercial version to clean up and shoot?
Either way, enjoy it for what it is - a great pistol with a long history. A lot of Canadians in Iraq in 2008-09 were still carrying Hi-Powers. I suppose they were Inglis pistols, and can only imagine how many times some of those must have been fired (and rebuilt, for that matter).