Drow weren't really in the 1e MM - they were mentioned along with grey elves (somethig about "dark as faeries are light" and "weak fighters, but strong magic-users" IIRC) - but no stats. They appeared in a module, then the MM2, I believe. They were freakishly overpowered as a race, because they were - as they are in 4e - meant to be higher level challenges (since, again, they apeared in a high level module - Vault of the Drow or Queen of the Demonweb Pits or soemthing).
3e 'fixed' that, and a lot of other logical oddities, by making them a race with levels, instead of a super-race even before levels.
But, it's not like monsters were formally designed to challenge a specific level in 1e or even 2e, that was a 3e concept, CR, and a very helpful one. The 4e equivalent isn't quite as clear to me, so far, but hopefully it works a little better. (CR/EL was really a little dicey at times).
AFAICT, adjusting a monster for a different level is closer to building a new monster than modifying an existing one - but builing a new one looks pretty easy. Pick role, pick level, decide if it's standard, elite or solo, and the relevant numbers are laid out for you. Come up with abilities and tweak for flavor & feel. Sounds easier than advancing or adding levels to a 3e monster.