Thanks for your comments guys. I have just found some of the same or similar comments on Wikipedia in English concerning the Dutch Indies/Indonesia, and this quote through one of the threads here that led me to Gunboards and a rather sharp discussion there...
"Quoted from Wikipeadia:
"The Japanese military also provided Indonesian youth with military training and weapons, including the formation of a volunteer army called PETA (Pembela Tanah Air – Defenders of the Homeland). The Japanese military training for Indonesian youth originally was meant to rally the local's support for the collapsing power of Japanese Empire, but later it has become the significant resource forRepublic of Indonesia during Indonesian National Revolution in 1945 to 1949, and also has leads to the formation of Indonesian National Armed Forces in 1945."
"PETA (Indonesian: Pembela Tanah Air - Defenders of the Homeland) or Kyōdo Bōei Giyūgun (郷土防衛義勇軍?) was an Indonesian volunteer army established on 3 October 1943 in Indonesia by the occupying Japanese. The Japanese intended PETA to assist their forces oppose a possible invasion by the Allies. By the end of the war, there were a total of 69 battalions (daidan) in Java (around 37,000 men) and Sumatra (approximately 20,000 men). On 17 August 1945, the day after the Indonesian Declaration of Independence, the Japanese ordered the PETA daidan to surrender and hand over their weapons, which most of them did. The Indonesian Republic's newly declared President, Sukarno, supported the dissolution rather than turn the organisation into a national army as he feared allegations of collaboration had he allowed a Japanese-created militia to continue in existence. During the Indonesian National Revolution, former PETA officers and troops, such as Suharto and Sudirman, formed the core of the fledgling Indonesia armed forces."
If you zoom into the pictures, you will see they are not the official IJA ShinGunto issue, but are 'Japanese' like in appearance. I hope this helps you to appease you a bit in your request, and generate some healthy constructive debate."
*** end of quote**
This actually would make this sword more valuable to me from an emotional point of view. If it was a decent copy of a gunto supplied to PETA troops (presumably an Indonesian officer) who went on to fight against the Dutch colonial forces as rebel forces, this would be the perfect explanation of how it ended up the hands of my father, *without* a scabbard (let's not call it a saya at this point). I know from his firsthand accounts that he participated in some pretty heavy fighting. Three years is quite a long time to be in a jungle war, and for Dutch troops, Indonesia with forward fire bases and patrols in the jungle was a lot like Vietnam later for US soldiers. I know my dad has held dying comrades in his arms, and has been forced to kill enemies at close quarters to defend his life (something he was very definitely not proud of, and for most of his life refused to talk about). It is entirely possible that the sword was drawn in battle by a rebel soldier against my father's unit, and it fell from his hand as he was killed or wounded. My father is now suffering from advanced Alzheimer so he will never be able to tell me what happened exactly.
The sword being of decent quality as such is not surprising if it was made by an Indonesian swordmaker. The Indonesians have always had a pretty strong local tradition in the making of knives and swords, machetes and mixtures of both (parang, klewang, sikin, pedang, kris, golok and dozens of others...). In their jungle country, a single blade would often be used as a machete and serve as a weapon. That may explain why there is no visible peg holding the handle to the tang: the Indonesian maker may not have intended to make a sword that could be disassembled, he might have considered that too weak if the intention was to chop wood a lot as well as to slash people occasionally... But he still used a real rayskin to cover the handle so it would be a proper sword for forces trained and armed by the Japanese. So, an Indonesian homage to a gunto ? I can certainly live with that, and I have learned something, which is the most important.
And just for fun, see the image below of a real Indonesian short sword/machete, a Golok, also brought back by my father. In that case, no question about its authenticity.
Just one note. The Japanese did horrible things to many civilians in Indonesia and other countries they occupied, and particularly to the 100,000 or so Dutch civilians they imprisoned in concentration camps in Indonesia. My mother was imprisoned in such a camp, lost a sister there, and has always carried that trauma with her. Several of her family's friends and neighbours were beheaded by Japanese officers using katana-style swords, in other words, guntos. The picture of sword-wielding Japanese officers and NGOs in the minds of people who were imprisoned and abused by them during WW2 is wholly different from the image that martial artists and sword collectors of today have of the samurai. As symbolic objects and examples of steelmaking, Japanese swords are of great interest; the image of slashing people with them is not something I would personally glorify.