I think a major point of my comment was not clearly expressed by me:
Customer does NOT own the tooling by any operation of law WITHOUT a provision in the contract that he does, in fact, own it.
We exploit that by making an upfront statement when negotiating the contract that we do not intend to maintain (or store at our expense) customer-owned tooling or equipment.
We explain the benefit this way:
If the customer wants to own the tooling, he should be responsible for insurance, storage, maintenance, repair, replacement, periodic inspection for suitability, etc. We tell him we would be happy to perform these for him for a specific periodic fee (paid whether we EVER manufacture a component for him with the tooling.)
Then we ask him how we would resolve any dispute that arose between us on the suitability of the tooling for manufacturing his component if he were to undertake the responsibility for storage and maintenance of the tooling at his site. The alternate of us owning the tooling becomes much more attractive.
In the instance of giant forms for sheetmetal or similar super expensive tooling, the contracts do, in fact, spell out all of these responsibilities, including how the inventory shall be maintained, notices, etc.
My suggestion for Mshell is to query all current owners of the tooling on exactly what terms are understood by them, get them signed off in writing, and vow to change procedures for all future tooling to be something more organized and user-friendly.
Alternately, in the absence of any previous understanding, Mshell's company could make a unilateral declaration of terms to the owners with the offer to ship C.O.D. any tooling back to customers (former customers?) who object.
This would be a good time to take inventory and determine how much of that tooling may be obsolete and the original owning company out of business (or in any event, having ceased doing business with Mshell's company.) You might be surprised how much dreck is in inventory.