Your original question was if a cello with no concrete attribution could be worth $100,000. After 3 pages, the only plausible clue was a colleague who was reminded of a Seitz cello he repaired 30 years ago. I spent decades as a court appraiser, and came to hate the question “what something is worth”, since it is a question that one cannot satisfactorily answer, rather one can only really search for comparisons. Often one must be satisfied that one cannot identify a 19thC maker, and be happy to have a nice cello. Everyone up to now has been too polite to point out that 100,000 for a cello that one cannot attribute with confidence would be outrageously expensive