Need a newer DRO readout that works with my older glass scales

I have a QMS 800 DRO and QMS 500 glass scales on my Bridgeport Series 1. The DRO is not functioning correctly but the scales are good. I am looking to replace the DRO head and need to know the specs for the scale encoders so I can match up my scales to a newer DRO readout. Does anyone have the schematics for either the DRO head or the scale encoders or simply know what each pin is used for? Here are some pics of the DRO head and encoders

Thanks for any information you might have.

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