Manchesterreg, at the start of my Hue project I was considering recreating the attack on the Treasury building in Hue. I came to the conclusion that there was nothing really available, commercially. At least not in 28mm. I've got the Grand Manner French chateau building that could (at a pass) double up as the Treasury building and some of the other Carentan range from Grand Manner look very similar to the colonial style buildings in that area. Not sure if Dave at Grand Manner is still doing business and it might be a tad pricey but that might be worth a look.
If you are into making your own terrain I don't think that it would be too difficult to make the Treasury building using foam core. I did start the project but then read about the fighting north of the river, in the Citadel, and decided to make the terrain around Phase Line Green instead. I'm currently, contemplating whether or not to make the Citadel walls and the Dong Ba gate (might be overstretching myself a bit though and could run the risk of getting bogged down in terrain making). If I return to the Treasury building idea I'll be sure to post a picture of my progress, if that helps?