Biggs. Briggs was pretty shitty skillwise (see 48 year old Foreman outjabbing him). I'd expect Tyrells jab and superior movement and pedigree to be the difference and he'd take the decision.
But even a 48 year old Foreman had strength and power to back up his jab. Biggs lacked serious power, and this was an often fatal handicap in his career, in addition to being prone to cuts and swelling and unable to resist being drawn into slugfests.
Briggs was a completely different fighter after three or four rounds. Biggs pretty much the same only he could box more in the opening rounds. Pressure is what drug him into brawls and Briggs lack of in the later rounds would probably allow Biggs to stay on his toes. Briggs was not a particularly good brawler either.
Tyrell Biggs takes this by wide decision based on his vastly superior boxing skills and fast hands. He would jab Shannon silly and use his footwork to get out of the way of Briggs’ best shots. I suppose The Cannon has a puncher’s chance in the fight, especially in the early rounds, but I don’t see him winning this fight.