Exactly what model and year cadillac is this? I can't make out the name on the side of it.?

The Wikipedia does list the '69-'70 models of DeVille as a factory convertible. I've seen mods made to later Cads by scavaging from those earlier years. The online pic you show does present a heavily modified, bling caddy. If they did cut the roof off, it makes the floor pan of the penger compartment very weak without adding the underbody cross torsion bars.