Adventurebug Congo/Gabon Border insight

Eventually we free ourselves from the deep sand tracks and find another way to head to The border post between Congo and Gabon on the Oyo- Francesville road/track is insight after some pretty lonely stretches, but magically countryside with wide open grassy plains scattered villages and some interesting driving conditions which could change by the day.
GABON here we come....well we hope I do not want to be turned back by Congo Immigration at the border between Congo Gabon as we do not have an entry stamp into Republic Congo due to our Boko track to Brazzaville missing the Congo border officials completely ...... yikes