Skull: article in Vietnamese that gives dates about when they will wrap up in Australia and start filming in Vietnam
http://thanhnien.vn/van-hoa/phim-kong-skull-island-khoi-quay-tai-ninh-binh-vao-272-659938.html
The short version, if you don't feel like using google translate is:
"Looks like "Skull Island" will wrap Australia around Feb. 18th/19th to head to Hanoi for the last month of filming. "
https://twitter. com/reeltourshawaii/status/689893171036291073
""Kong: Skull Island" prep is working hard to get things ready for filming to begin in Vietnam on Feb. 27th."
https://twitter. com/reeltourshawaii/status/689884005848580096
"Kong films in Vietnam 2/27 - 3/15"
https://twitter. com/reeltourshawaii/status/689883418386034688
There's also an article in English with less details about dates
http://www.thanhniennews.com/arts-culture/king-kong-prequel-to-start-filming-in-vietnam-this-february-58410.html