Old School Character Sheets:

Here's a character sheet from the mid-70's. Hand-written on steno pad paper, I'd guess it's from about 1975 judging by the stuff it was found among.
In 1981 I played in a friend's AD&D campaign, here's one of my character sheets from that campaign.
House Rules:

Here's a PDF of the house rules I used with a Holmes-edition Basic D&D game back in the 80s and 90s. Among the things I did was use mana rather than memorization to manage spellcasting.
And here are some rules notes from my current OD&D campaign.
Class Writeups:

Here are writeups on some of the classes I use in my present OD&D Campaign, detailing how they work in my game. I base my classes (mostly) on the originals, articles from The Strategic Review, and The Dragon:
I've also got character sheets specific to my campaign that detail a lot of the rules I use for classes:
Generic Character Sheets:
I've also got generic character sheets that others can use in their campaigns if they wish:
- Alchemist Character Sheet
- Cleric Character Sheet
- Druid Character Sheet
- Fighter Character Sheet
- Illusionist Character Sheet
- Mage Character Sheet
- Paladin Character Sheet
- Ranger Character Sheet
- Thief Character Sheet
If you wish to create your own character sheets based on mine, here are the original word processor files. They were created using Apple's iWork word processor, Pages. They use a number of fonts, the most critical being BankGothic Light and Medium. These can be replaced with the free versions of these fonts to get the correct formatting.
These files contain the full infoblock for my campaign. Edit them as you please for your own campaign.