I used a micro pneumatic switch that is activated by a cap screw that I inserted on the side of the front strut. The head of the screw hits the lever of the micro pneumatic switch to activate the door closing sequence when the nose gear is in the full up position.

I plumbed the opening of the doors on the down line to the retracts, i.e. doors open with the deployment of the retracts, you don't need a delay in this scenario...