Ray, Those would be Peabody Martini's not Pederson. 
But those are indeed the find of a lifetime! Congratulations.
I have no clue of their value.

Those rifles were not uncommon in the British Empire. I lived in Australia for a while and often went to the local collectors club. Turns out the New South Wales Rifle club during the Creedmore period used British issue Martinis for long range target work.  They ordered some Peabody Martinis from the US for club use and to have true target rather than service rifles for International competition.

There is a good book written on this called the Target Rifle in Australia and they are mentioned again in a localy produced history of the ANZAC rifle range in Sydney.

One of the collector club members had one of the Rifle clubs Peabody long range rifles. It was in "Attic" conditon. Light rust and very dirty. Sights were missing. Under the grime was full engraving and beautiful wood.  When the Australian gun laws changed he was very anxious to sell it.

I toyed with the idea of buying and restoring but it was way past my ablity and could not find anyone who would go in with me on the purchase import and restoration. This was about 1998 and we figured the rifle would have had 4-5 thousand dollars invested restored and landed in the US. At the time a good Sharps or Remington was about the same price. Should have bought the rifle and put it away since no doubt it would be worth much more now.

Boats

Rich, I would also be interested in those Peabody Martini Rifles. I am currently in the process of restoring a Mid-Range. I have not been able to bring up the pictures on the photo site. Will try again later this evening. You may contact me via email at  rfitz.ma.ultranet@rcn.com
Looking forward to hearing from you. Regards,FITZ