Hmm the sampans are actually a pretty timeless design and the painting of eyes and bright colours is traditional. so I'm pretty sure you could paint them much as in the pics for the 1880s. Many photos show a semi cylindrical, woven grass or reed cover on these boats as a refuge from sun and rain.
The other boat, the bigger one in the second photo, from Barrage range is a Yabuta junk. Those were commissioned for use by the South Vietnamese Navy as patrol vessels and built in Japan for use in Operation Market time, the interdiction of seaborne supplies and infiltrators from the north during the Vietnam War. Motorised and definitely modern, although similar types probably predate and certainly still do exist in the region.