It is worth investigating the statute of limitations on the contract signed and the enforceability of the pay on demand clause.
https://en.wikipedia.org/wiki/Statute_of_limitations
https://e-justice.europa.eu/content_...mits-279-en.do

My opinion form reading the above is that a certain point the Nokia N950 recipients are no longer bound by those contracts and the devices become abandoned property in your hands so you can do with them as you please.
Of course this is an uninformed personal opinion not any kind of legal advice.

What was the date of the dev contracts to get a 'free' N950?