I don't see a manual product registration page anymore on the support site, so I assume this is handled via the partner program. If Dedicated Networks is not a Juniper partner you can search the serial number to see how it is currently in the Juniper support system.
https://supportportal.juniper.net/s/serial-number-entitlement
The partner can also get you any support contracts or licenses. A simple one to deal with as an individual is CDW. But you would need to verify first that the device serial number is clear to get a contract. Some devices on the secondary market were used to get a discount from Juniper for upgrades and would not be eligible for any support or license.
If you work with Juniper professionally, your sales engineer at work, either partner or Juniper direct, may also be able to help with a not for production access for software or licenses.
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Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP - Retired)
http://puluka.com/home------------------------------