That driver is either a 902 , 908 or 909 model .
The 902 and 908 each have a 7/8" exit while the 909 has a 1" exit ( measure the size of the mesh screen , not the cardboard gasket ) .
The 902 has the most HiFi sounding diaphragm in it of the 3 models ( assuming it's stock and not replaced with some ChiCom junk ).
Without taking off that loading cap, there's no actual way to determine which model that driver is ( apart from mounting it a horn a running a frequency sweep >. since the 908 has the least amount of HF ) .
Great Plains Audio ( GPA in Oklahoma ) sell replacement diaphragms ( the 34647 - 8 ohm model for instance ) that are very HiFi sounding.
- GPA's diaphragms are made from the original Altec tooling ( purchased when Altec went bankrupt ) .