NP. My condolences for your family's loss.
My point was to question the assumption that it was a non-original part. If it is the winter safety and it came in that configuration, I would think that a 60% reduction is a bit low, as you note from GB research, especially if you are considering purchasing from the estate based on your low valuation.
I would attempt to purchase at fair value just to keep it in the family for future generations, if no other family member had similar intentions.