Thanks Rovert. The scope in question dates to 93, so i guess it's safe to say it's a M8.
I have three FX scopes of varying ages, one a FX3, one a FXIII and one FXII. All are marked on the objective. I would assume that yours would be also, though I'm not certain. A call to Leupold and they can tell you by the serial # what model it was sent out as.....
Kaiser Norton