Given my "retirement" has turned into starting on the ground floor in a new field of endeavor; maybe shoot for 25th anniversary of the 2nd edition -- it came out in '92 +25= 2017 so that gives me three or four years.
When mom finally left the book go out of print we had the opportunity to keep reprinting. From my view, it has enough errors and "not enough information" entries to let it go.
Given the brave new world of electronic books etc. a new edition might well be "digital native" with a "print on demand" aspect for those who'd want paper copies.
One thing that keeps happening is "new information." For example, I was going through the 1897 Canadian patents via a google books digitized volume of Canadian Patent Office Record. And there was a patent matching the "ADJUSTABLE TWIN" (S#917 ). At what point does one cut off research and focus on arrangement of existing content.
Regards, Stan S.