Black boy peach trees

There are two black boy peach trees here.  One came with the property, in the garden around the house and has produced fruit every year since the move in.  The other out in the orchard was bought at the Southern Woods nursery two or three years ago, and has only hinted at producing fruit this year.

The household tree has always had fruit that were a fuzzy grey/purple.  They have the "bloody" flesh and juice that you would expect from black boy peaches.  Personally, I don't think they taste particularly good.

The orchard tree has young unripe fruit that have been and still are what can be described as a green with a red blush.  It'll be interesting to see what the fruit will be like when ripe.  Will they be different than the household tree?  Will the tree even be a black boy peach?

It reminds me of reading something about fruit trees, which speculated that often we have no idea what rootstock trees we buy in New Zealand were grafted to, and whether we were even getting the variety grafted to that rootstock we thought we were getting. Would I know if my Discovery apple tree was some other variety? Probably not, unless it was one of the few varieties I could recognise. Until this year, I assumed that I should be getting what it said on the label, then it became obvious several months ago that my white currant bought from Mitre 10 was actually a red currant.