Hi Tony. 67 1066 is the casting number. When your parts book arrives you'll find this number doesn't appear, only the closely related part number for a complete cylinder head assembly. This is true across the whole of the BSA parts listing. Pistons confuse even more as the number stamped on the crown is close to, but not exactly, the number in the parts book which is the number for a fully loaded piston.
BSA only used two styles of A10 Iron Heads. Early "thin fin" used on rigid and plunger models, then with the swinging arm frame came a similar casting but with a bigger fin area....your 1066 type.
Alloy heads and cast iron heads have different valves, collets, caps. They also use different head bolts. Valve springs are an exception, Alloy Head A7 Shooting Star springs are the same as iron head type, but A10 Rocket Alloy Heads have their own springs. Iron head common hardware parts are broadly the same from start to finish and all head types have lower spring cups. Valve collets, caps and springs are common to A7 and A10 Iron Heads.
Detail changes came as the engines were developed over time.
All will be revealed when your parts book comes. Camshaft number is stamped on the end of the cam, and can only be seen when the cases are split to expose the blind bush end of the cam in the drive side case. To split the cases, the camshaft can remain undisturbed, it does not hinder dismantling.
Swarfy.