Hi, thank you for your question! I have completed thousands of musical instrument appraisals and will be happy to help with yours.
Unfortunately, there's no way this organ can be appraised online. A pipe organ needs to be appraised in person by a qualified pipe organ company. I would recommend contacting a local pipe organ company (they are throughout the US) and hiring them for an appraisal. For the sheer price you paid for the work done in 2004 you should want this done in the best way and that would be as described above. Best wishes
Sure thing. Good luck!