Q) I am looking for a schematic symbol not found in the Scheme-It library, where would I find this? Do you have parts that have more pins than the original or do you just have one symbol for them?
A) Not all the parts have schematics in the Scheme-It library. What you can do instead is build your own IC with the custom symbol option. Go to Custom Symbols > Symbol Primitives and you’ll see different shapes of Part Body, as well as Top/Bottom/Left/Right pin’s. The body can be dragged onto the schematic, and the pins can be dragged onto the appropriate spots on the custom part body. Using this system, you can build most any IC schematic symbol you should need. If you find a schematic symbol that you need, but you need it to have more I/O’s you would still need to create a custom symbol as you cannot add pins to the schematic symbol that was loaded from the Scheme-It library.
There is also a HowTo: Create Custom Parts video as well.