[cctalk] Friden Flexowriter models

I have recently acquired a Flexowriter. It looks very much like the one shown on this page - https://moca.ncl.ac.uk/iomedia/pt4.htm The identifying points are - blue color keys - tape punch and reader (both appear to be 8 bits) - white and red lamps on the front panel beneath the Friden logo The serial number plate shows F_V as the model and S P E C as the coding. Is anyone familiar with what this model is? What does the coding refer to? Peter