If you really feel that someone has used a product like jb weld or simular try heating up the waterpump flange a little. Most plastic cannot stand much more than 200 degrees in my experience. The heat should be enough to degrade the sealant so you can achieve separation. Of course make absolutly sure you have got all the bolts removed as on a few types of waterpumps I have overlooked one on occasion. I live in an extremely corrosive enviroment so dealing with rounded off fittings is just a way of life. Just looked in manual for 123 types. To access one bolt you have to rotate slot in balancer to get it apparently. Also pretty sure that pressure line to head is also a pump retaining bolt and wonder if you may be missing one of these as you still have fluid coupling and perhaps fan partially obscuring your view. You should have five normal bolts out as well as one hollow one that feeds line to head before trying to remove pump. Best of the season.