28 old Chinese/Vietnam cash coins with hole for identification. Fake?

Hi,
I bought these coins as multi-lot. For me all this - like Chinese rebuses)). So I very much hope for your help in their identification (KM-number, year).
Maybe some coins are fakes (or some Fengshui knick-knacks).







Coin №5 looks for me most suspiciously. It shines. Central part is unnaturally porous (bubbly). Feeling as if it was made at home by beginner-fake-maker)).

Coins №24-28 look very perfect (in comparison with the rest). Smooth surfaces and accurate edges. Coins are thin (≈1 mm).

Any of these pictures can be increased to big size if to open it in a new tab/window.

Regards, Victor

a fast look:

1 https://en.numista.com/catalogue/pieces2724.html
2 https://en.numista.com/catalogue/pieces41543.html
3 can not see
4 vietnam, 10 van
5 1 cash av: jiaqing rv: boo guwang, guandong (not on numista)

17 can not see much but i think: https://en.numista.com/catalogue/pieces22675.html

18 https://en.numista.com/catalogue/pieces31487.html

21+22+23 = https://en.numista.com/catalogue/pieces26024.html

6+10= https://en.numista.com/catalogue/pieces19755.html

same type
7+8+9+11+12+13+14+15+16+19 = https://en.numista.com/catalogue/pieces1133.html

24-28 same type
https://en.numista.com/catalogue/pieces6817.html

If some coins look like fakes? (especially №5)

Your n#5 is genuine: DH# 22.505

It's a cast coin and that one is more porous than usual.
coins 24 to 28 were produced by struck machine.