Batboard

I have purchased one of these units it does all seem to be working well however the oxco is slightly off frequency, i have found the control for this on top of the oxco and also the calibration output control for the for the power meter ref but do not want to just adjust them in case theres a specific procedure to follow.
Adding a 10mhz signal to the rear from a GPSDO does make a dramatic difference however i do like to use this thing portable so would be good to get it as close as i can on the oxco.

Can anyone help with this procedure

Does anyone have a service manual they would like to part with ?.

Thanks