Date: 1969. Owned by Jim Priebe
The extra tubing is for the F Rotary valve. The 79H is essentially the same as the 78H, except the 79H has the F rotor attachment while the 78H doesn't. It is a #3¾ bore (0.522").
What Conn said in 1966:
Popular with professional "studio" men, ideal for symphonic and jazz. Produce[s] a rich, dark tone, throughout somewhat lighter than the 8H and 88H. Brass bell. The 79H has F rotor with E pull. Bore size .522". Bell 8". Length 45 1/2".