the crash site, based on the location of the burials seems to be close to the Czech border. Perhaps the theory of a drop from a special duty squadron could tie in. I have looked through the ORB for 148 and can't find a match, I would suggest having a look at the 37 Squadron ORB, I know that they were operating out of Italy conducting both bombing raids and drops to partisans etc. I take it that there is nothing to aid with identifying the remains when they were moved in 1946. It may of course not be an RAF aircraft at all and could be an American aircraft operating in support of OSS operations. Im guessing that MREU didn't go to the area in the immediate post war years, possibly suggesting that this isn't a British aircraft. Perhaps the 856th Bomber Squadron, one of the 'Carpetbagger' Squadrons operating out of Brindisi might be a possibility.
I will try and have a look through the 37 Squadron ORB later today when I have a bit more time, but this is going to be very difficult without a more detailed timeline.