Well for $4 as a start it's lookin' good. Four days 'til end o' auction should see it with a significant increase by auction's end.
But in the original post the question was can you use the rectangular hood etc.
The aspheric 35 summilux uses E46 filters and the pre aspheric E 41 or Series 7 which suggests a different outside diameter and incompatible hoods.
The early aspherical(90-94)indeed does have a notch in it to keep the rectangular hood from rotating. I don't have a good enough image to verify that the newer models do also.
Regarding the lens hood on Ebay UK. OK, it is not square - it appears to be the Leitz 12504 model. It fits both the pre-asph Summilux and the pre-asph Summicron.
Originally Posted by David H. Bebbington
Yes that is the hood delivered with the (preasp) lux from new.
Alas it is not very effective other then as a drop stopper, if you fit a series VII filter it is even less effective, as the filter is hardly 'hooded'...
The current clip in cron hood is a 42mm push on clip in ring hood. This is rectangular and works perfectly at f5.6 or smaller.
The lux does not have the keys to stop it rotating and the lugs on the aperature ring may just touch, the nubs on the hood. An elastic band will stop the hood rotating.
The rectangular hood turns the lux in to a nice lens as opposed to a flare queen...