What do you plan to use this tractor for.  I'll try to consolidate and correct the information from the posts above.  You have a display that is unlocked for RTK and the previous user was receiving RTK corrections via a radio.  We are unable to determine if that is a 450 or 900 mhz radio.  Also, you are not unlocked for GLONOSS which will potentially result in less reliable RTK fix.  IF you have a radio based RTK network in the area that provides CMR corrections you can subscribe to that.  Many of those have been abandoned in my area.  A second option would be cellular delivered RTCM messages from a provider such as Digifarm.  You wouldn't need any unlocks for this but would need some additional hardware (that they will provide).  Your next option (if unlocks are still available through a dealer) would Centerpoint RTX.  This would be satellite delivered corrections with RTK accuracy.

Personally, I'd be cautious about spending money on unlocks for this display.  It is essentially 3 generations old in the technology world.  If I were using it (I still have one) I'd go with Digifarm as you'll be able to move that hardware and subscription to a new display easily.