He claims to have a "organ and piano restoration" business and will do the work himself. However, he does not wish to move the organ, claiming it would be damaged,

does not compute.

Restoration very often requires a near total dismantling of an instrument, so it can be removed to a pipe organ workshop, restored, and reinstated. Very often, when this occurs, the only thing that remains in place is the casework, and sometimes the wind chests if they don't need re-leathering (although they often do). There is only so much you can do in situ. At the bare minimum, in situ restoration is more difficult if for no other reason than it is cramped to move around.

So something seems odd about that claim to me. If he really did own an organ restoration business (and was more than just a casual traveling service technician) then he could indeed remove the instrument, restore it, and make use of it elsewhere.

As for giving over churches for profane use, about the only thing I personally find remotely palatable is as a concert venu, and even then, it leaves a bad taste in my mouth. Coffee shops, restaurants, gymnasiums, and the like are all terrible things to do to sacred spaces.

Imagine, if you will, the following scenario:

Would we EVER permit it that, once a church closed, there was no more need for the sacred vessels, ergo they could be sold in a garage sale and used privately in someone's home just for kicks? Good heavens no! They are consecrated vessels! They were made for one thing, and one thing only. It seems to me that if a chalice was indeed never to be used again, it should be smelted, not given over to profane uses. The same seems to hold true for Catholic churches, with rare exceptions for their repurposement as retreat centers, specialty chapels that are only opened on rare occasions, or museums.

sure they could. It would just become a condition of the sale of the property it stands on. Or some of the funds of the sale could be used for the demo.

At any rate, not my dog and pony show.

https://savingplaces.org/stories/former-churches-converted-into-art-centers

I have seen some that have worked out. In every case, though, a lot of $$$$ and more than one person is needed. One guy buying an old building and tinkering with the organ in his spare time doesn’t sound like that to me, unless he’s buried the lede and already set up a 501(c)3, has job descriptions ready to go for admin/artistic/outreach staff and funds on hand to pay them for a couple years, and an endowment set up to keep it going in perpetuity. Otherwise I think these kinds of conversions happen when Irma talks to Doris and Harold and they get all their friends to volunteer and donate, and serve 500 pancake breakfasts until they can buy the building and get rolling.