Eviction notice for tenants who have paid to make home habitable

[Sarah Thompson]

Hello! I would be so appreciative for some insight about this situation. Here is a broad overview: 

Tenants rent from elderly family members who do not have the means to take care of an old home which sits on a large piece of property. Tenants have made major upgrades to the home ALL from their own pocket over the past 4 years, including repairs to make it habitable. A brief overview of the repairs include patching the old leaking roof multiple times in multiple locations, dealing with a rodent infestation in the ducts, flooding beneath the house and more. Property has been maintained with 37 acres of mowing (legally required fire control), dealing with downed trees and a long list of other items. Tenants have lived in the home with no written contract or lease, all verbal due to the family dynamic. Tenants have always paid their rent on time and have receipts and documentation for all repairs and upgrades. Not one penny has come from the home owner. Essentially, these tenants have been care-taking the home and the property while still paying full rent that was accepted and cashed by homeowner. All upgrades were verbally approved by the homeowner along the way, however one has recently passed. There is now question of the remaining homeowners mental status due to age and declining medical issues.

Tenants received an eviction notice with instructions to not remove anything from the home (except their personal belongings), including appliances with the threat of legal action if they did not abide. Tenants have purchased ALL of the new appliances and have documented proof. These tenants have increased the homes value with all of the upgrades (new flooring, carpet, exterior paint, replaced rotten siding etc) and the repairs made were absolutely necessary to make the home habitable and safe with the verbal approval of the homeowner. At the time of repairs, there was promise of reimbursement which has now been gone back on. All of the original (very old and broken) appliances, fans and more are still in storage and photos were taken along the way from before and after. 

Can legal action be taken by the homeowner if the tenants remove the appliances and items they purchased with their own money? Can anything be done in a sticky situation like this to recover costs of necessary repairs of the home to make it habitable?