The bayonet could be a duffle bag bring back, thousands were. But to collect a war souvenir first hand meant you had to be near the firing line. Many souvenirs went though many hands before they got home.
Everyone traded for souvenirs. Rear area enlisted hoarded booze, which was completely convertible to anything. The best booze was bottled in the USA, the next best was brewed locally from whatever containers that could be made from fuel tanks and water containers. Pop skull was never as good as the refined stuff from back home, but it hit the spot.
Pilots had it best as they often flew to Australia where the trading was good.
Our last WW2 Veteran was second wave Iwo Jima and Okanawa. He was Navy communications and landed with the Marines. His job was to relay messages from the shore to the command ship. He brought back a bayonet, one sword, an Arisaka rifle. He said his ship disembarked in San Pedro Harbor CA and everyone's duffle bag was opened up. If you had an Arisaka rifle, you got in line and had the crest ground off. I was surprised about that as the Japanese did that, but Americans, doing that in the USA? . Sammy said there was a pile of grenades, land mines, etc, that were taken away. Boo hoo, can't take that
Japanese type 99 mine back home.