They don't look at all like the picture in the Francis A Field Guide to the Mammals of South East Asia! That's odd. They do look like the pictures that come up on google for Grey-bellied Squirrel though.
I also did see what I identified as a Grey-bellied Squirrel in Kaeng Krachan that looked a bit different so I'm not sure what's going on there, probably seeing it in forest rather than out in the open.
