Here is an update on my build. Sorry the pictures seem a little dark due to the dark plastic.
We have had a lot of discussions over at the armorama forum about whether Vietnam M113s could be used to cross rivers etc. It seems like the US M113s were very seldomly used to cross waterways while Australian M113s were used more often. Also there are different opinions on whether M113s armed with ACAV kits and the 106mm recoilless rifle were actually amphibious.  
Anyway, in the end I ended up being a sucker for the Korea camouflage and Tigers head insignia on the Korean version of the M113. (I will try to find a picture of this and post it) 
Also I have decided to show the M113 in 2 to 3 feet water brown water, so there should be no need to discuss the whole issue of whether the M113 used its amphibious capabilities often or not.
The main construction is done now. Next is painting and work on the diorama. 
My idea for the diorama is basically to construct a box of clear plastic, make some swamp seabed and fill in clear resin mixed with a little bit of brown paint. Any other suggestions are welcome. 
My LHS does not have clear plastic, so I will have to try and find an alternative source.   
 
 I have made the M113 all closed up due to a number of reasons:
1) I wanted to show the box like shape of the M113
2) I want to show the M113 taking fire and doing water splashes
3) There are no Korean crew figures included

