You say you have pictures with bombers in them. Can you see the tail of these bombers? The 315th Bomb Wing at Northwest Field had B-29s with a Diamond on the tail with either a B, L, Y or H inside the diamond. The 314th Bomb Wing at North Field had a Black box painted on the tail with either an M, O, P or K in while on the black box. I know that Northwest Field had some F-5s (P-38 recon version) and after the war some P-47s. I don't know if North Field had any fighters.
If you can share a picture or two of a photo with a bomber in it or a front bumper of one of the trucks, it may help some of the folks here to give you some better information.
I did a search of the rosters I have and found a PFC Malcolm L. Fisher in the 587th Engineering Squadron of the 75th Air Service Group, Northwest Field Guam. His service number started with 18 indicating he enlisted in either Arkansas, Louisiana, New Mexico, Oklahoma or Texas.
No luck yet finding a Thurman Blackard, but I'll look a little deeper through the rosters.