I haven't seen an original listed in years and was wondering what they are going for these days....if you could find one.

Cliff -

All that I have seen sell during the past 50 some years have sold for exactly half of the doubled sale price.

I have an original that is inscribed by two different pens.

One inscription is "One of original books given to me by Dr. Pope. Joseph L Russ  Presented to R.R. Litchfield 9/16/32"

The other inscription is in a different pen with more artistic script and simply states "1918 Ishi pix."

Do you know Russ or Litchfield?

"All that I have seen sell during the past 50 some years have sold for exactly half of the doubled sale price."

I can't argue with that.  

Russ and Litchfield do not ring a bell but I'll keep an eye out.