So I understand:
1) You have a USB with the HP Recovery Media on it.
2) You made this using the HP software when you first set up the machine.
3) The HP Recovery media is Windows 8.1, the same version installed on the machine by the OEM.
good so far?
4) You upgraded the machine to Windows 10
5) You recently removed the HP Recovery partition (normally D: Recovery)
6) These questions are difficult to answer:
Q: Has Windows 10 changed the D: recovery partition during the upgrade
A: The upgrade would not change the HP D: \Recovery ... a clean install might, depending on how you Clean installed.
or will it be the exact same image the computer shipped with?
-> The upgrade might have created a new recovery partition or expanded the System Reserve partition. I'm not exactly sure what you're trying to determine.
Q: Also, any idea how I can get the recovery files back on the D: partition?
A: Yes, but you don't need the partition since you have the USB Recovery media. I'm not sure if the HP F11 key would still work or not after the upgrade. That's the real power of the partition, being able to boot to it. You can do that with the USB.
I have a few HPs and I always create the HP Recovery media, then remove the D: Recovery drive to reclaim the space (and free up one MBR partition). My HP machines shipped with four partitions allocated (System Reserve, Windows, Recovery, HP_TOOLS) - this makes it difficult to manage an MBR initialized drive.
As long as the HP Windows 8.1 Recovery USB is good, you don't need D:\Recovery.
If you really want to get it back, I'd like to see your Disk Management
If you've already downloaded the custom MMC, go to Step 2 to launch it and then grab the screen shot.
Step 1: Download this zip file (contains dmDskmgr-vd.mmc)
Step 2: Double click dmDskmgr-vd.zip to open the compressed folder
Double click dmDskmgr-vd.mmc to launch the custom Disk Management console
You'll get an output similar to this:
Press Alt+PrtScn to grab a snapshot of just the Disk Management window
Open Paint and Ctrl+V to paste it, then save the image
Attach the image to a new post.
Option 2: Use Disk Management in the x-Menu (right click the Windows logo, select Disk Management)
Select View > Bottom > Disk list
Maximize the window and grab the screen shot.