Four postcards from Sicily dated 8-1-44,could be from the RAF,looks like the jeep driver is having his photo taken on the despatch riders motorcycle,the despatch rider is also on two of the photos. Below is the jeep driver. Below is the jeep driver in his jeep,with the despatch rider standing. On the two photos below the jeep driver is on the despatch riders motorcycle. Below a closer view of the unit insignia on the motorcycle. My error this should be the closer up view.
The RAF style roundel on the jeep bonnet was used as an aerial recognition sign by the Army as well as the RAF in the middle east.
The "AA" emblem on the front mudguard is described in Howard Coles formation badges book as Anti Aircraft and Coast defence units RA, he says it was used in Italy but its quite likely to have been used in Sicily too.
The 'RAF' roundel was the standard air recognition symbol in MEF / Italy. The jeep driver has an army pullover on so he's probably army too. The chap beside the jeep seems to be wearing an American shirt but this was not uncommon with the British forming part of 15th Army.
As Rob says, likely to be ack-ack. The horizontaly divided arm of service colour suggests RA too, but I can't trace '147' anywhere although it is close to a number of Indpendent Brigade serials. Were there any independent brigades in Sicily ?