Note: this is just going to be in outline form of major events in Thailand/Siam from the collapse of the HowCo-backed government to June 1940.
1937: The Dutch and Danish armies commit to stamping out the HowCo-backed government of Siam. By the time they are finished, so many of the old politicians had been tainted by HowCo connections that no group was able to get any traction on the national stage. Only the presence of AEGIS warships and military personal prevented the situation degrading into civil war.
1938: With the last elements of HowCo removed from Siamese territory, a sense of normalcy returns. Danish peacekeepers are still present, propping up the barley functioning remnants of the government.
1939: The first half of the year continues much like 1938. Come the second half, a shocking revelation is made, some members of the royal line were still alive! Many felt that this was Siam's ticket out of the slump that she had been in. Many overtures were made to the potential new king, Ramkhamhaeng III and he finally agreed to come to Bangkok and attempt to restore order to Siam.
Early 1940: Ramkhamhaeng III proclaimed that the Republic of Siam is dead. In its place shall rise the Kingdom of Thailand. The democratic government was to be kept, but now only had legislative powers. The executive powers would rest within the monarchy. The legislative leader, known as the High Senator works with the King to handle matters both domestic and foreign. The legislative branch has the power to make and pass laws, but if the king desids to overturn them, he can do so. June of 1940 saw the government reforms effectively completed, allowing the long silent Thailand to finally be heard on the world stage once again, this time for its wonders and wisdom, not for the dark acts that had taken place there. Long live Ramkhamhaeng III!