Three patches

I've not yet posted 25 posts so can't put these up as traders. Will do it, because I don't collect Vietnam War patches. Got these three ones as traders with a load of other items. Now, the topic is difficult, thanks to fake-makers. Anyhow, my friend and a collector who sent these to me is not unexperienced in identifying. Shortly... before I put up these to be traded, I liked to hear what you say.

Two are semi-identified. The first one is "engineers" (stamp height 72mm) and the second one "logistics coy" (stamp diameter 63mm). The third one is a mystery. BK TOAN 3 (height 95mm). My reference books and the net sources say nothing. Take a look and let me know if you have ideas considering that third patch.

Thanks,

Shotgee

40th construction battalion
4th Logisitical Command
The last one is a fantasy piece made for the tourists market, in Vietnam within the last 20 years.

Thank You, Bob,

Not a huge surprise that the third one is a fantasy one. Too clean and no smell.

Shotgee