Looks like it´s an IMF / ELAC 8/28 BR. This late version with the "rips" you find at the IMF ALS 40 II. Please check the diameter of the voicecoil.
This are the only specs I have:
You can find it at the Falcon-Acoustics site also...
You should have in mind, that the old ELACs (and KEFs too) go out of specs, because of the rubber surround getting harder. If you want too use them, they need a looong play-in. I suggest to do that, befor testing them in an enclosure...
