Great pic Chris-looks like he's wearing his 'white bucks.'
Woolfolk used a Parker as an amateur, but went Pro in 1910
http://www.la84foundation.org/Sports.../SL5420023.pdf
Mr. Woolfolk Henderson, of Lexington, Ky., who has been known as one of the leading amateur trapshooters of the country for two or three years past, on January 1st, joined the professional ranks, as a representative of The Peters Cartridge Company, shooting Peters shells, du Pont powder and a
Lefever gun. Mr. Henderson’s scores during 1909 indicate very exceptional ability, and this with his consistent loyalty to Peters ammunition have their logical result in his employment by The Peters Company. He is sure to, add rapidly to the already long list of friends he has made far himself and the goods he will represent. In the year 1909 from April 29th to December 22d, Mr. Henderson shot at 9495 targets, breaking 9008, an average of .9487 per cent (using a
Parker). Beginning with the Southern Handicap at Nashville, Tenn., May 4th, 5th and 6th, he shot at 8995 targets, breaking 8597, an average of .9557 per cent., a record which has never been exceeded or equaled by any amateur shooting at this number of targets.
Throughout the year he used Peters factory loaded Ideal shells with 3 1/8 drams du Pont smokeless powder, 1 1/4 oz. No. 7 1/2 Ch. shot.
I didn't find any mention as to when he went back to Amateur status, or started using his Parker again. Peters continued to advertise his using their shells however.
He had a big year in 1914. In addition to winning both the GAH Handicap and Doubles, he had the High
Amateur Average, AND the High Amateur Average in 1915 at .9753.