You have a WWII-vintage UK-made aerial camera lens. "UU" was the code for Dallmeyer, that's who made it.
I've seen two flavors of such 14"/5.6 lenses, neither with six elements. Tessar types and Cooke Aviars.
Go count reflections again. If the lens is a tessar type you'll see four strong reflections and no weak ones in front of the diaphragm, two strong and one weak behind the diaphragm. The weak reflection may be very hard to see. If it is an Aviar, you'll see four strong reflections, no weak ones, on each side of the diaphragm.
I have a TTH-made 14"/5.6 Aviar, ex-Air Ministry. Amazingly sharp wide open, also very flary.
All of these monstrosities will cover 8x10.