JBL M30 and M31 drivers , needing date and info

[macaroonie]

Hi all , can anyone throw some light on the JBL M30 and M31 drivers , approx vintage etc,
I'm in the midst of a discussion on another website forum and there is a lot of fog.

Specifically trying to ID a driver where the model no. has been scratched out but it does have the Mxx decal intact and the Magnet pot is the more squared type.

Here are pics of the accused. Sorry no chalk numbers worth using or legible yet. Now that I see it clearer I'm leaning towards a recone et some point , the edge treatment looks too clean to me. Update , we have a serial number: 11257

It's in a Twin Reverb BTW Cheers everybody.

[Allanvh5150]

As far as I remember, the M30 was a re release from JBL of the D130. The M31 was the same as a D130F.

Allan

[macaroonie]

Thanks Allan , another update , seems like its an M35-4 , hence 4 ohms which is what the Twin Reverb wants to see.

[Allanvh5150]

There were a few more as well. M11 and M12 were K110's. M21 and M22 were the same as the K120. M41 and M42 were K140's. M45 and M46 were K145's. And the M51 was a K151. The M35 was also a K130.

Allan.

[macaroonie]

So what was the date ish of this M series , as in there is hardly any info in bugle or LH library. ?
To be honest I have never seen one of these ....