Yes, the drawing and handwriting style look like Sternbach, but since Jein led the modeling of the 6' and 2' Enterprise-D models for ILM, it would make sense that he had them in his files.The Ebay seller has listed a few more:
Pretty sure these are both sketches by Rick Sternbach:
vtg 1980s concept art - Star Trek Next Generation Enterprise specs Greg Jein v8
vtg 1980s concept art - Star Trek Next Generation Enterprise specs Greg Jein v7
From the TMP Official Blueprints set.This is just a poster I think:
vtg 1980s concept art Star Trek Motion Picture Klingon Ship specs Greg Jein v11
I have no idea what these are, are they even Star Trek?
vtg 1980s concept art - Star Trek Next Generation ship specs Greg Jein v4
vtg 1980s concept art - Star Trek Next Generation ship specs Greg Jein v6
