Hello! I was recently given one of these cameras... and he seems to be in lovely condition (the possibly with the outer lens missing? no-one i've shown it to is 100% sure there should be a lens there ) and I'm planning on running some paper through as a test. HOWEVER i have hit a snag when it comes to metering.... there are 4 apertures, handily labelled "1-4" :| Any idea roughly what these correspond to, or at least point me in the direction of someone who might know? Thanks!