The RWD Nova disappeared in 1979. Flat fuses were first used around 76 or 77 but I don't believe they were ever used in a Nova. The fuse panel looks like an OEM style. The flashers are for turn signal and hazards and the black box in the upper RH corner is a "multi-function alarm module" that would signal door open + keys in ignition, lights left on with key off, or seat belts not fastened. Is the fuse panel marked with circuit ID's in white letters? Brake, Stop, Cluster, etc or maybe with numbers? That could help match it up. Some '80s trucks had the flashers on opposite corners like pictured. Check out the fuse boxes and instructions on this page.
http://www.rowand.net/Shop/Tech/GMATOStyleFuseBlock.htm