Hey congrats. I own a pair and have seen several others over the years for sale. Your midrange drivers should look the same as the woofer and have FB stamped on them. I've never seen mids like that before so I think they have been replaced. Do a search on the auction site and you'll see the correct mids and probably some replacement mids if you care to make yours original.
Nice find...I think the A in the model number represents that it's finished under the grill (like yours). I have a thread on some SP2000's that I recently posted...Pioneer put a lot of love into their speakers, they didn't mess around with build quality, the cabinets are top notch. For an early 70's speaker they were one of the few that actually looked cool with/without a grill. I have a feeling the CS & SP Lines are really going to appreciate in value in the next few years...
Yup, those are definitely not original midranges, they look like modern car speakers. I'm glad you enjoy their sound - but frankly, whoever switched out those mid-drivers transformed Kabuki into a clown car.