Hi jim,
I built the pbr years ago (it's a very nice kit I think) and I have 2 (or 3??, dont know my own stash) waiting. One of them I'm going to superdetail, that means including an engine and the jaccuzi waterjets etc etc. I started on that one but other things got in the way. also have the 1/48 swift boat, actually just as a guide because I wanted to scratchbuild one in 1/35 but that project is also on hold.
here's a nice site that has several vietnam dio's
http://www.ediorama.com/bbs/zboard.php?id=namdio
you have to sign in to see more of it.
If you want to see some of my own pictures just let me know and I'll email them to you.
good luck with your diorama's!
kind regards
Mark