silver leaf disease -opinions/help

Ok so I have a plum tree with silvery looking leaves, a gardeners corner member (Shiney) gave me some info and i cut a branch to check for brown staining. The attached pic is the outcome, if its silver leaf im going to have to take the tree off at the main trunk so I want to be sure. Is there Anyone on here who would know if the staining in the pic is likely to be silver leaf????

 

It does look like silver leaf, spudlike. But I can't say I'm 100% certain, sorry.

 

I've got a couple of trees in my garden that I suspect of silver leaf.
But I'm also not sure.

One is a laburnum, which is noted for having pale sap wood and very dark heart wood, so every branch I cut above a certain size has dark staining.

I'd be more likely to go by the silvering of the leaves, both my suspect trees have certain branches where the leave have a silvery appearance in late summer, and then start to fall early.