I would have expected more Carcanos in the mix, since a couple of Italian division-sized units surrendered to the guerillas in September 1943 and turned over all their weapons to them.
Conversely, I wouldn't expect many German weapons since the Germans withdrew in an orderly fashion in October 1944. In fact there was a secret agreement by the Allies not to attack the Germans as they withdrew.
Lots of SMLEs, that were airdropped by the British, can be seen in the pile. But the Stens (that were also airdropped) were evidently kept by the guerillas for the next round.
Hardly any American weapons. There was an American OSS mission to the guerillas (my late father-in-law was part of that), but the supplies were mostly from British sources. American aid really started coming in during the 1946-49 second round of the civil war, and of course it went to the Greek government and not to the guerillas.