Homebrew PCBs

Alan,

The copy/paste functions are part of the "magic" of Eagle. :)

Actually, they sort of suck sometimes. I've modified library devices 
many times, and still can't remember the exact procedure I use to get 
a variant created and ready for edits,etc. I sort of fumble through it 
each time. I'm guessing here, but it was maybe something like 
selecting an available item in the device/package list, and putting a 
"new" name in the text entry box, then clicking OK,add,new, or 
whatever they've got, and I think it may ask if you wish to create the 
new item. I also think I may have had to do it separately for the 
individual lib. elements (package,symbol,device?), giving them each 
the new name. (sorry no Eagle on this machine here) 

Unless you already know this, the copy weirdness is usually a matter 
of using the group command to lasso everything you want, changing to 
the *cut* tool, and then "right" clicking (I think) somewhere in the 
group. Nothing will appear to happen, but you'll then have a clipboard 
full of junk you can paste into a new item.

Mine are usually more like what I guess you're doing, where I want to 
keep most of what they've got and put a close variant in the same 
library. My changes, however, are often in footprint or package 
tweaks, rather than pinnings.

Hopefully someone here knows more specifics,

George

PS- LOTS of times, I'll go for DIP packages and blank IC's, rather 
than trying to create a permanent library item, but it's usually when 
I'm working from the board, and don't care about the schematic.