Where can I find placards and decals for the interior and exterior of my plane? Is there any source other than Beech?
There are generic kits sold by places such as Aircraft Spruce and Chief Aircraft. Aerographics is a source for model-specific kits. Check their link on this (BAC) site.
http://www.aerographics.com/kits.html
Here is a direct link to Chief Aircraft’s offering:
http://www.chiefaircraft.com/cgi-bin/air/hazel.cgi?action=serve&item=/Aircraft/Decals/InteriorPlacard.html
Which leads to one more observation. Read the Type Certificate for your Skipper, downloadable from BAC. It will spell out all the required placards. If it shows only a required part number for a given placard, you are supposed to have to use the exact part number. On the other hand, if it includes specified text (with or without a part number), you should be free to provide your own placard.
Z3 Graphics reportedly offers custom aircraft graphics, though I have not used them myself. They are located in Fountain Inn, SC; here is their link:
http://www.z3graphics.com/