Considering the wide range of lesions and the several possible chronic causes of lameness that can be inferred from them, my original suggestions stand, more specifically:
While lame paddock rest, assuming she will be quiet there, and NSAID’s. When sound return to pasture. Remaining sound at pasture light riding might be attempted.
Steroid injections in the coffin jt (easy) and navicular bursae (difficult) may be helpful. My choice would be methylprednisolone (DepoMedrol) due to its longer action however some veterinarians believe that there are more deleterious effects on the joint and systemically than with other medications.
A common recommendation would be shock therapy, and this would relieve the lameness. However it should be looked upon as a neurectomy at least early on. Considering the permanent lesions I don’t think the horse should be exercised until the nerve blocking effects wear off.
Of course all these treatment recommendations have downsides and possible contraindications. You can read more about them as we specific articles on all these, just run a search on each subject. These suggestions need to be discussed, pros and cons with your veterinarian for only you and (s)he can come to a consensus as to what is best for horse.
DrO