Here it is all assembled.
What i've done is to lay him on his side and spray black primer on the underside.
Then stood him up and glued in place.
A word about the base - this is the tried and tested way of mine of:
buy an el cheapo picture frame (49p from Wilkensons), take the glass out and replace with the backing card.
Put in an uneven layer of Das Pronto and move it around until happy (can't stand dead flat ground in dioramas). Once dry, its lifted out then glued down. It has a tendancy to shrink so the edges around the frame need filling before putting the grass down.