Recently I consulted an expert in the restoration of Wurlitzer 125
needing "the works", and the final repair estimate exceeded the known
value of the instrument by $17,000.

Was this an extreme estimate?  Where does one draw the line on
restoring an item if the labor cost to repair and rebuild exceed the
value?

It seems that antiques of all categories suffer the same consequence.
A neighbor of mine has a depression-era cedar chest that needed a light
sanding inside (to get the cedar smell back) and refinishing outside.
The bill was $1100 for a chest valued at about $200 on the antiques
market!

Rich Schaffer
Silver Spring, Maryland