need schematic for BLC 80/05 multibus board

I am a volunteer at the Oakland Aviation Museum. We are trying to restore a 1980 vintage cockpit training system. It contains a Multibus board by National Semiconductor, model BLC 80/05 (along with dual CA Naked Minis, and several other 8085 boards). Evidently this is a knockoff of the Intel SBC 80/05. We are trying to locate documentation for this board so that we can repair it. We are in desperate need of a schematic. Even an SBC 80/05 schematic may help. Any help or pointers would be greatly appreciated. --jon CONFIDENTIALITY NOTICE: This electronic mail message and any attachment hereto may contain confidential information of Meyer Sound Laboratories, Incorporated and is intended for the personal and confidential use of the designated recipient(s) only. If you are not the intended recipient (or responsible for delivering the message to the intended recipient), you have received this message in error and any review, distribution, or copying of this message or any attachment hereto is prohibited. If you have received this message in error, please promptly notify the sender and permanently delete it from your computer.