For getting glue residue from old, poorly executed seam repairs off, try Bestine, a liquid found in art supply stores. It removes the residue, but leaves LP jackets, hi-fi casework paint, etc. undamaged.
Seamzeazy record jacket repair
This is pretty cool. I have a few LP jackets that could use these.
http://www.seamzeazy.com/iframe-srchttps/playervimeocom/video/190772866-width640-height360-framebord...
http://www.seamzeazy.com/iframe-srchttps/playervimeocom/video/190772866-width640-height360-framebord...