I got my grubby hands on a Minister III. Everything fires and clicks but the RF is off. I did my regular googleing but I've hit a brick wall with this one. There is a screw under a screw-cap on the back but it doesn't turn and I don't wan't to force it. I did remove the cover plate from the accessory shoe but I'm not sure where to locate the adjustment screw. Short of removing the top plate, which I tired and got stuck on the film advance lever, how would I calibrate this nice old machine? Thanks. Oh, it came with a bonus 20 shot roll of Plus-X from whoknowswhen inside. I'm going to develop it at some point.