I've been trying to find an adapter for a Late 2014 MBP Retina SSD. Standard msata didn't fit, and from a few consumer reviews of other enclosures and adpaters, it seems to be uncertain if one exists. Its a "mini PCI-e" interface, but its been hard finding an enclosure using that term that doesn't end up being an msata one. The SSD installed has 28 pins (12+16). I've seen some mini PCI-e to usb adapters, but they are from sketchy sites with no product reviews. I was hoping someone here had experience with this and could recommend one that worked for them.
Seems like OWC Envoy Pro is what you are looking for. Though it is kinda pricey avout 140$ now.
Compatibility table is like this so yours is included.
According to https://discussions.apple.com/thread/5446239?start=15, "because 2013 macbook SSD is PCI-e X4 version, it can't be read in SATA or USB port .It only can be read in PCI-e X4 adapter card". They have a link to a PCI-e card product that has a slot for the SSD to be inserted internally. It seems there aren't any USB interface options.