Shoes worn by 1973 Triple Crown winner Secretariat and the legendary Seabiscuit will be auctioned by Illinois-based auction house Mastronet Inc. starting April 5.Two Seabiscuit shoes will be available -- one worn during his match-race victory over War Admiral and another worn during his win in the Santa Anita Handicap. The Seabiscuit shoes came from Seabiscuit owner Charles Howard's personal secretary, Carolyn Schmidli, according to a press release issue by Mastronet's public relations firm.The shoe Seabiscuit wore against War Admiral was made into a presentation piece while the Santa Anita Handicap shoe was fashioned into an ashtray, as was Howard's tradition, and given as a gift.The Secretariat shoe was worn during the first two races of his career, including his first victory. It was mounted and engraved by James Gaffney, Meadow Stable's exercise rider.More than 1,800 items in all will be auctioned by Mastronet. Bidding ends April 21-23. More information can be found at www.mastronet.com.