1 Photo - Jul 21, 2014
Photo: Here is an updated version of my DnD 1e to 5e Conversion Tool:

DnD 1e to 5e Conversion Tool — 2014-07-21.pdf

If you are interested, you can download the math behind my tool (download it to your desktop to view). Excluding Stirges, all other creatures I tried converting from 1e average to within < 5% of their actual 5e stats. Should work well then for lower-powered monsters. Not sure if the math scales well to higher levels; will see what the Monster Manual gives us and then I can revise (or maybe the DMG will give us this guidance).

Stan Shinn's 1e to 5e Conversion Math 2014-07-21.xls