Just doing some searching indicates the 4530B was a 3 point attachment backhoe with its own pto operated hydraulic pump, and some photos suggest it was not a really large one, with a 90" digging depth. Tractordata.com says the 4530B was an alternate backhoe for the L2850, so it probably should fit.
If you are not familiar with 3 point backhoes, be sure to read up on the issues surrounding their use. They put a lot of stress on the tractor rear end, and can be hazardous to the operator if something breaks. You may need to add some reinforcing, such as for the top link attachment bracket. For light duty use though, a used 4530B in good condition might be very useful.