Thank you for all the ideas and thoughts. While new glass units (E5 and G5) are sexy and appealing I don't think they are the right fit for my partners and I given our AP and the necessary add-ons for proper and full functionality.
@Jerry 5TJ my first thought was vacuum failure but it turns out not to be the case. The primary vac is doing its job as is the back up vacuum, both working well and not the culprit. I'll PM you to discuss further.
@201Mooniac a PM will be headed your way as well.
@jazztheglass The G5 is a great unit. We kicked around the idea of dual G5's but my understanding is that G5's will not drive the Century 21, could be wrong, but that my current understanding. Also, your experience of loss of AI's in IMC is harrowing and one I'd rather hear stories about than tell first hand stories about. I'm glad things worked out well for you and I hope you sent that controller a fine bottle of scotch!
I'll post a panel pic later to show what we're working with. Thanks again for your thoughts.