It's the same hood, as the plastic hood for the current 35 Summicron ASPH.
There have been two different Leica numbers assigned to this hood, as it came with different lenses (I think, also the current 28/2.8 ASPH).
#12526
I think, the earlier number assigned was #12525
In any case, you have to remove a small tab on the hood, preventing it from properly seating on the pre ASPH Lux.
There is a lengthy thread somewhere on RFF, describing some neat solutions regarding alternative hoods and filter holders.
Dirk, 12526 and 12524.. (I am trying to find a way to mount it on the 35 Summilux pre without needing a pin. 🙂 )
its very simple. what you do is stick on both side of the 12524/12526 inner mount ring 2 strips of black electrical tape. it will reduce the diameter of the hood inner ring just slightly, keeping it snug in to place.
this is my configuration, i still maintain the hood mount clips/tabs, but they're actually not neccessary because its so snug. the hood lives permanently on my lux now.
photo.JPG by Blind Idiot, on Flickr
What a fantastic thread !
My first Leica lens... here I go then :
Cheers
Jean-Marc.