I would like to talk about a product I made and put up on DriveThruRPG.
My friends and I had a mishmash world, where D&D and AD&D were treated as the same thing. Plus we had Unearthed Arcana in our set of shared books. Yes, we all shared books among our group of players which could number as many as 14 people on a given night.
It wasn't easy to combine all these dissimilar products but one of the aids we had was our own computerized character sheet that we could print at will. It was created on my Mac 512 in Mac Draw.
It was excellent (click to order).
From the title panel, you can probably guess that we had a ton of multi-classed characters and a lot of wacky rules to combine everything from D&D, AD&D, and UA. We actually learned a lot from this process of creation.
First, no one liked Cavilliers or Theif-Acrobats. We like to use a homebrew method of character attribute generation, 4d6 with the lowest die discarded and order as you see fit. Humans received a plus one to a single stat as desired. Half-elves received either human or elf attribute bonuses.
We tried to implement weapon adjustments, but it was very cumbersome. We did like weapon proficiencies.
As an oddity of all of our shared worlds, no one invoked raise dead or reincarnation spells, the only thing that was used was wish or alter reality spells. And infrequently at that.
It was often enough to cause problems in unexpected places. Encumbrance was a problem as characters willed a bunch of stuff from one to another. So our rule was all items had to fit on the character sheet, despite the actual size. A full 1/3 of our character sheet was dedicated to just equipment.
I cannot tell you how many times one of our DMs would have to deal with "my character reaches in his pocket and pull out a ring of X", only for that player to discover that the thief now knows exactly what he stole 3 sessions ago.
Anyway, a few years ago I found a copy of this sheet. I scanned and uploaded it to DriveThruRPG to share with others. It is one of my more popular items, probably because you can download it for free. If you really like it, you can actually pay for it. It is PWYW, but I suggest 99¢.
In uploading this document, I realized there were flaws, such as missing all of the Theif-Acrobat skills. The layout could be improved and so on. I created a newer sheet that had some of the old-school style captured in the first. However, it is sharper and cleaner as it is a wholly digital product rather than a scan. It too comes with the original character sheet.
Good things come in threes, so I created a third variation of a character sheet. One that no one asked for: The 20-page character sheet! It's actually a single sheet of paper folded into a flip book. I used them for a B2 campaign. My kids and their friends enjoyed them so much that they kept them.
So if you like old school goodness, please give my 3 character sheets a try.