Jack Youngblood Signed Blue & Yellow Throwback Custom Football Jersey w/HF'01 Go to amazon.com Related posts Where to find jack youngblood throwback jersey? DescriptionJack Youngblood signed blue and yellow throwback custom football jersey with 'HF 01' inscription. Item comes with a Schwartz Sports Memorabilia tamper-proof numbered hologram and Certificate of Authenticity which can be verified online.