Many thanks to all for the feedback!
I managed to get Al on the phone for a very pleasant hour-long discussion yesterday afternoon. He strikes me as an affable, pleasant fellow, clearly knowledgeable about long rifles and I plan on visiting with Al tomorrow, time permitting, at his home just south of Fredericksburg, VA.
With respect to the rifle above, I sent the consignment shop an indication of a willingness to make a prospective offer of $1500 along with details and information from this thread, some other personal e-mails sent directly to me by members who know Al personally, and the results of my phone discussion with Al himself. I will advise all of the feedback that I receive.