Hi Barb, I did find your article earlier through a Google search and it was my inspiration for working with Verizon to get this set up. Thanks for writing it.
I did try to follow the instructions in the article but they didn't work for me. I wasn't able to get the iPad SIM to work in the Surface using those instructions.
This afternoon, after I posted, I did some more work with Verizon. I was finally able to get the tablet activated in a store.
First, and most important, is that the SIM card that was needed for my Surface 3 is an Android-compatible nano SIM (part number DFILL4FF-NFC-A) rather than the iPad/iPhone-compatible nano SIM. So the short process that worked for me was: get a DFILL4FF-NFC-A nano SIM card, have Verizon put the SIM card into a floor model nano-SIM-compatible Android device (the new Samsung Tab S2 uses a nano SIM) and add that device to your account, boot up the Samsung and confirm it accesses the internet over 4G/LTE, take the SIM card, put it into the Surface and boot up the Surface. It will take a few minutes for the Surface to activate. Wi-Fi needs to be off while the devices are activating.