Westinghouse model #OAC21X4

I am trying to save my old Westinghouse double wall oven. I have tried replacing elements in both ovens, but one oven still doesn't work at all and one only heats to about 200 degrees. I would be happy to even get just one of the ovens working again. I would appreciate any recommendations for further troubleshooting. Thank you.

Thanks for the reply, Gene. I do not have any documentation on this oven that was in place when I purchased the house in 1986. I have learned that thermostats and other parts are no longer available for this model, but I do not understand why I cannot pull the oven out of the wall, trash ALL the electricals, and start from scratch with all new components. I do not even need the clock or the timer to work. I just need the old metal box to get hot so I can cook in it. I have to virtually demo and reconstruct 1/3 of my kitchen to accommodate a replacement wall oven so this is my motivation for making this oven work again. People put all new guts underneath old car bodies, I do not understand why this cannot be done with an oven. Has this never been done before?

Thanks, Gene. I understand about having a licensed pro do the work. I certainly do not want to lose my entire house to fire over this.