Can I get an idea of what people think about this situation? Yes, one of these guys is me.
Let’s say Larry owns two pieces of the same musical equipment. He agrees to lend one to his friend John pretty much indefinitely on the basis that Larry was not using them at the time and had no foreseeable need for them. John indicated he would take care of any necessary maintenance of the item. Larry knew John would treat the item with care and was just happy to see it get some use, so happily offered it to John who was going to make use of it. It is an old piece that is inclined to break down from time to time. Say both John and Larry are well aware of this.
After John has been using the item for about two years, it breaks down. It requires repairs to it costing about $600, about a third of its value. There is no suggestion of any mistreatment of the item by John; it is just a component that expired through age or whatever.
The question is whether Larry should contribute to the cost of the repairs. I suppose it might be relevant that John has just loaned Larry a piece of musical equipment on an indefinite basis and with a view to buying the piece. That is an instrument that would be worth around $1200-$1500. The item that Larry has loaned to John is one he may eventually sell to John if John is into buying it, but otherwise John will just go on using it anyway.