I've often said that for me, House-rules ARE playing "By the Book" in regard to Advanced Dungeons & Dragons 1E.
In several places, the noted author of the books, in this case E. Gary Gygax, specifically tells players the game itself is in the hands of the Dungeon Master. He also specifies that DM's are not chained to the book as solid rules but to make the most fun and playable game they can and if a ruled is hand-waved or a dice fudged, etc... so be it.
Because of this, there are a rare few DM's/GM's who do not have a piece of paper or an online list of House-Rules somewhere. With House-rules, AD&D is not just "a" game, but it has become "your" game.
On internet forums and blog sites and wiki's and any number methods of interaction, DM's share their own House-rules with others and they "borrow" House-rules if they sound good. Customization and personalization of the game is complete.
I have considered AD&D 1E to be a two-sided thing. A game in general and a game for a specific purpose. The history of the game is well known enough, along with notes in the books themselves, to indicate that specifically, the rules included are there to make tournament play something consistent. Everyone running a tournament game has the same set of rules and players don't have to learn a new set of rules as they move from table to table at a convention, etc...
Then there is the general play of the game in which the rules are more like guidelines and there is more on the spot creativity and spontaneous change in the game. That's what we do at our home tables.
I think it behooves DM's and Players all over to have discussions to clarify and have common interpretations of the "rules" for those times when a "tournament" game is happening. At the same time, I think it's going overboard for folks to try to demand that a book rule "must" be adhered to strictly in a home game. It's a different arena and the rules are no longer "rules" at the home table.
That's just my two cent though.