Only 4 or so years late to this party having just bought an Agiflex with a slow curtain problem for £26 but I have to say on the subject of there having to be a pool of working cameras so don’t use a particular one in case you break it - the OP has never used his camera so he doesn’t know if it’s working or not. The argument is therefore a non-starter.
If he tries the camera and it works then he might (arguably) be justified in retiring it from active service in order that it can be one of a dwindling pool of (as far as was known at the last attempt) working examples. If he tries it and it doesn’t work it was never one of any dwindling band of working cameras. If he tries it and it breaks well, it wasn’t going to be much of a candidate for the dwindling band if it only had a life expectancy of one roll of film.
As camera repairers know, if you don’t use working vintage cameras, they stop working. The old grease goes solid. They rust. The lenses get fungus especially in leather cases apparently.
A camera, like most machines, has a limited lifespan. It is designed to be used until the end of its lifespan. Then it might, or might not, be repairable. But at least it wasn’t wrapped up in cotton wool. It was used. A famous guitar player who shall remain nameless once said, when asked how often he cleaned his guitars, “I don’t clean them; I play the (expletive deleted) things!”
As things stand he doesn’t know if it works so at the moment it’s not a camera because a camera takes pictures. And it’s certainly not a working example because it hasn’t been given any “work” to do. It’s a door stop.
So IMHO it’s ridiculous to suggest that he should use another camera while this one is left in a bag.
Let some light into it - that’s what it’s for. That’s what they are all for.
Sorry for the rant but I feel quite strongly about this. I’ve got valuable old cameras that I use. Should I stop? Should I retire them?Absolutely not. The men who made them would turn in their graves. They didn’t make Museum pieces - they made machines that take pictures. Until they stop taking pictures and become door stops.