A few months ago, I posted about the brief Swords & Wizardry game I was in. One of the posts addressed how our group used Labyrinth Lord to "fill in the blanks" of missing or incomplete information, or at least to consult it before making a ruling. As I prepare for my AD&D1 game, I find that I am doing this with, of all things, Hackmaster. For instance, I am using the monk AC/Open Hand tables, as I think the 1st level monk being AC 10 is a bit silly. I might take 2e's proficiency rules, at least in some form, or Hackmaster's skill system. I also have a skill system sent to me by a fellow blogger I need to review. The equipment lists in HM are more extensive and I plan to use them as well.
In short, I find that I am taking things from a variety of sources to fill in the blanks. My game will be some kind of freakish hybrid of several editions and systems. I suppose this is probably true of just about any game that has ever been played.