Identification of Dell Recovery Media

Okay, it's dumb question time.... :emotion-2:

I'm going through a load of unlabeled USB drives of varying sizes, from 8GB upwards. Several of them appear to be Dell OS Recovery drives that I've created at some point, and then stupidly not labeled. I'm sure I meant to label them, I just got distracted in the moment before I managed to.

The problem is, I've got a number of different Dell systems. There's a Precision M4600, a Precision 5510, an Inspiron Mini 3010, a Venue 11 Pro (7140), and a now dead Venue 8.

How do I know which computer the recovery media I have in my hand is for? Frankly, how do I work out which version of Windows is on it easily? 

I know it's not going to be the M4600 - I never created media for that, and it's unlikely to be the 5510 as I actually bought USB media for that when I bought the laptop, and that's nicely labeled. So... is it for the Inspiron Mini, or one of the two Venues, or is it even older than that, from one of the many, many Dells or Alienware systems I've had over the last few years? 

I really wish there was a nice .txt file or .inf file that I could just look in and see, but I can't find anything like that for the life of me :emotion-18:

So... anyone got any bright ideas?

Here's the root directory of one of the drives...

...then digging in a little...

...and then a little deeper still...

...but none of the XML files, batch files, or registry update files seem to have anything other than an OEMID set, originally enough, to Dell.

I'm open to any bright ideas (or even not so bright ideas :emotion-5:)