You might wish to approach it a little differently. What would it be worth in its original stock and does the owner still have that stock? Now, what is the premium for the Ultra stock and what would that stock fetch if sold separately?
I have a feeling that barrel and action in original stock + Ultra sold separately might yield a bit more.
I understand the sentiments that you express however you may wish to consider the following points:
1. This is a public forum and provided that members observe the rules they are free to make relevant posts.
2. Unlike some other forums we are not permitted to provide "valuations".
3. All the posts in this thread are relevant to the item offered for sale, they offer factual information and none refer to condition or offer opinion.
4. The Sales section of the forum pleasantly free from any form of recrimination; I certainly cannot recall seeing any adverse comments.
5. If you do not wish to accept that comment may be made, then there are other forums where this does not happen or commercial sites such as Gunstar or Egun.
I believe that the information that members have provided may be of siginificant assistance to Greg in concluding a successful sale of his rifle.