Apparently something on one of my 500c/m bodies: While checking it out (running through the shutter speeds and apertures on my 80 CFT*) prior to taking it out on a hiking trip next weekend, I did something to lock up the shutter. I was able to remove the back to have a look inside but cannot see anything amiss. That said, I cannot remount the A12, nor can I remove the 80mm. Meanwhile the shutter remains open and a large flat pin on the bottom right (looking into the body) protrudes....
And looking through my other Blad stuff testing it out...my 50mm does not open up: changing apertures on the barrel has no effect. Time for some professional help...