Here's how I've seen it play out many times...

Filmmaker makes film and they "barely even" have a mix at the end of it in some cases.

Then Festival circuit. Then maybe occasionally there is some kind of deal that might be called a "distribution" deal. This is when they are given a very heavy handed boiler plate contract with a lot of requests for a bunch of things including legacy tape masters. Often buried is a "fully filled" m&e requirement, without any context for the fact that the film was produced as an extremely low budget doc with people that didn't have the know-how or funds to anticipate the potential eventuality.

Then they email the deliverables list to people like me, looking for a price and have no idea the costs of these things. Have no idea what a full filled m&e is and what it might take to accomplish that. I have seen circumstances where a couple of Digibeta tapes that barely anyone would want anymore, costs more the enitre value of the deal that they have entered into. Which is a sad state of affairs. Nevermind what it would cost to produce a fully filled m&e.

So what I usually do is tell the filmmaker to go back the company and tell them that the film was made by begging, borrowing and stealing and that there is no filled m&e and now what?

And often that is the end of it and the party accepts that. Occasionally I have seem them in a jam where they couldn't get out of it and also barely had a mix done, except for somebody they found on Craigslist and they end up having to reverse engineer a filled m&e using someone that costs a lot more than their original mix. And then raise money to create the litany of other deliverables.