Scott- I believe he uses Graphic Conservation out of Chicago. That is also the company that did my Horner 1903 American League Composite, though admittedly it was right before I owned it. I look at that photo every single day (it's the only thing on my wall behind my desk) and smile a little each time. Graphic Conservation Co isn't cheap but they are good and they are quite well known among auction houses.
Also, I suggest you call them and chat with them. They could answer any questions better than most of us, especially as the the processes they use. All I remember personally is the few times I have spoken with them they have seemed quite knowledgeable.
http://www.graphicconservation.com/
***edited to add.....I will leave that stuff above as I know they do great work...however, I emailed my friend after I posted and he said he uses this person..
I use a guy in Rochester, NY. His name is Gary Albright and his no. is 585 624 xxxx. His email is garyealbright@juno.com.
I will give out the full number to anyone, through PM, but I don't usually put others phone numbers in threads...when I don't know much about them. He must be good if my friend uses him
. I don't know him personally or through business...
.