One thing I would do in metering is walk up close even with the spot meter. I am guessing the soligor is somewhat affected by ambient light as I know my digital Pentax is. I would have walked up and metered the wall inside with the graffiti and hoped I could get it to fall in a high zone 3. then I would have metered the white outside and put it in a high zone 7 to see where everything falls. I wouldn't have worried about any of the middle tones.
Dennis