Pathfinders

Robert Frederick Morriss enlisted in the RAF in 1936 and was originally ground crew. On 1 11 1943 he appears to have been promoted to acting flight sergeant. At this time he was based in Oakengate and then on 1 12 1943 he was sent to Gransden Lodge, where he remained until the end of the war. He appears to have been Mentioned in Despatches in the London Gazette on a number of occasions 2/6/43, 30/5/44, 4/10/44, 1/1/46, 12/12/47 and 16/2/48. I would like to know if he did actually take part in Pathfinder missions, are there any lists of crews or any information at all at the National archives about Gransden Lodge, can I find out why he was MID? Also there is nothing on his papers about any medal entitlement, can I find out what he was entitled to?