Put all the right hand fingers and the pinky key(s) down when you play the A.  Then only the left hand has to move and, if your hand position is correct, that should be a simple efficient movement as we have discussed previously.

That and practise scales.

I think I've still got my old Otto Langey book somewhere.

Let me clarify how the key work functions. The lower joint is standard Boehm system. The only difference is that there is no linkage to the upper joint as there is no need for an alternate Eb. For the upper joint, Eb is fingered xoo|ooo. E can either be fingered oxo|ooo or by playing an Eb and using the first trill key or the sliver key. F is normal but F# can either be played with the first or second finger.

The plate with the vent hole is there to help with the altissimo like on bass clarinet. This is needed because the first finger tone hole is now a semi tone lower, meaning it is less effective to just lift the index finger. The plate is connected to the third finger ring so it will close automatically when you play an altissimo note.

Ah! So it's arguably better than the usual bass clarinet mechanism where you roll your index finger forwards.  Thanks Jared. 

It's a really good system but I think would be hard to learn.  No other woodwind I know of has anything similar.

... and we have the silver saucer characteristically wittering at length about an instrument he's never heard of before.  I wonder what happened to him.

I'm not entirely sure because I've never actually played one and don't quite know how the mechanism works.  Most likely it's for the altissimo - C# and up.  My guess is that raising the LH index finger for those notes probably causes something else to open on these instruments and it behaves as a tone hole rather than a register hole.  They fixed it with this key, the same solution as is used on the bass clarinet.

Honestly looks identical to a regular Boehm except for the plateau'd first key.

Seems like it doesn't do much for you except give you that little pinhole on the first pad, a la bass clarinet.

Look again.  There are 2 holes and pad cups under the (rather long) A key.   T X00 000 plays Eb,  T0X0 000 plays E natural.  The intervals are thus the same in both hands hence the name.

I can't see for sure but it looks like there's no connexion so long Bb is out.

Some of these had no side keys at all and were missing the Eb/Bb cross key. 

Maybe @jdbassplayer will drop by and tell us more about it.

Neat! That's an Albert system with plateau keys. You don't see those around very much at all.

A real shame about the lower keys though. Someone tore those off with great force!

Sax fingered, I'd say, not Albert.  Look at the RH tone hole arrangement.   Cabart made sax fingered oboes too.

It's just a different way to implement the 7th ring.  No better or worse than the usual way.

I take that back.  There is a small advantage in that the D#/A# cross key is excessively high with the normal full boehm arrangement because it lies on top of the extra vent cup.  With the doughnut that key can be at the normal height.