plum fruit has brown dried skin patches?

Hi, my damson plums (I think it is damson, dark small fruits anyway) all seem to be covered in dryish brown blemishes, some have the odd patch and others are almost covered.   I have been searching on google but cannot seem to find what it is.  I don't think it is brown rot as that seems to be a wetter rot and also seems to work quickly.  The plums have been like this from almost the outset, or at least since they were 1.5cm diametre.  I have a newly planted victoria plum tree planted about 5 feet away and the fruit on these are perfect.  Not many fruit on the victoria but it is the first year.  I am worried that the disease will spread to this tree?  I will try an attach a picture of one of the affected damson plums.  It is a bit blurry but the best I could get with my mobile phone.   I am hoping there is some way of treating the tree so this does not happen next year?  I would say that this years crop is probably a gonner.  Any ideas on what it is and how to deal with it would be greatly appreciated.  Many thanks

A lot of my damsons are like that. I assumed it was some sort of scab so I am still using the fruit which is fine inside. Its happened before but this year is worse.

If seem to remember it's a form of russetting cause by bad (wet) weather, unsightly but harmless. Unless someone knows different.