Hmm I'd have to look up that model number, but the "C" is typically for Celestion.
Are there any numbers/codes written on the arms of the basket?
It's certainly the original speaker.
What threw me was in the original picture, the dust caps don't look like any of the usual Celestions, and also, I've never seen a 15" Celestion in a Trace cab that was mounted that way.
I'll have to check as the cab is put back together now. I didn't notice anything when I had the speaker out. It sure sounds killer though.
For reference, this is what is sitting on top:
I just noticed the faint handwritten pen markings with a serial number on the back of the amplifier panel of my Trace Elliot V 4 V-Type bass guitar amplifier reads T 607 /988/ 395 ?

reminiscent of a faded graffiti sighted on a West Sacramento,California Union Pacific Cotton Belt grainer train.

