Well, the Apo Lanthar arrived this morning and it's mint. Some bits of dust but no haze in the lens at all, and cosmetically could have been made yesterday. So nice to get something in better condition than even advertised. It's light, small, beautifully made if a more silver shade of chrome than the M3.
It even has the same filter size as my other Leica lenses and the lens cap fits over it. Just delicious and the Voigtlander 28-90 adapter fits perfectly (apart from now lacking an M mount lens holder)
Now for a few tests!