HJ,
there is an enthusiasts book available in the UK called 'World Military Out of Service' (WMOOS); this lists all the known warbirds that are displayed around the world (listed by country). It also includes gate-guards, museums, and dumped and derelict aircraft.
For Laos it lists Savvanakhet, Vientiane (2 entries) and Xieng Khouang.
For Vietnam it lists 22 locations - too many to list here. But since you mentioned Bearcats, there is one displayed near the airport at Ho Chi Minh City.
Cambodia has just 2 locations listed - Pnhom Penh and Siem Reap.
The book is not the 'final word' on the subject, as things move around all the time; some are moved away for refurb, and then replaced, some move away and never return, and others still appear literally from nowhere! I am sure that there are still aircraft out there waiting to be discovered, or fully identified.
PS. Why is Thailand such a 'no-go' area for you? I'm intrigued!