Chinese Empire, Chinese Republic, 1 pre-Meiji Japan

Dear experts,
may I ask for your help one more time?
8 of these pieces are from the time of the late Empire and the First Republic of China.

What embarrasses me is that even coins almost identical in design may (slightly) deviate in thickness, or have a different character in the middle, etc.
Some of them are not present on the catalog at all; I am pretty sure I identified this one (third row, second one), but it is not on Numista yet:
https://www.ngccoin.com/price-guide/world/china-provincial-anhwei-province-20-cash-y-37-cuid-1046571-duid-1288415

Two or three of them may be of this type, but I am a bit surprized by the difference in diameter, which is visible (up to 2 mm, although in other details they perfectly match the picture, with different mintmarks in the middle):
https://en.numista.com/catalogue/pieces18177.html

The one in the bottom left is 4 mon Kan'eitsuho, as I could nearly identify on Numista's catalog. However, Numista lists 3 different coins under this description, and i may miss some minor details that would allow me distinguish between them.
The comment says: Meiwa-sen has a brassy coloration, Bunsei-sen is a reddish alloy, and Ansei-sen is a dark color. My guess that mine is Ansei... any other details that would allow me to decide?
https://en.numista.com/catalogue/pieces162214.html
https://en.numista.com/catalogue/pieces156603.html
https://en.numista.com/catalogue/pieces162216.html

Would you have suggestions about their types?

Hello

I think that your 4 mon coin is this one
https://en.numista.com/catalogue/pieces162214.html

like the first one
you can see the three different colors on my picture

Thank you! I will correct the coin information on my collection.

Regarding the Chinese coins:
the top row (all three) most probably correspond to this one, and the mark in the middle is the year rather than the mintmark:
https://en.numista.com/catalogue/pieces9281.html
Second row, the left one is apparently Y# 408 Kansu 50 cash 1926 (not yet on Numista):
https://www.ngccoin.com/price-guide/world/china-provincial-kansu-province-50-cash-y-408-151926-cuid-1046130-duid-1291693
Second row, middle:
20 cash, early Republic (no idea about the rest)
Second row, the right one is 20 cash Xuantong:
https://en.numista.com/catalogue/pieces18177.html
Third row, left: Xuantong 1911 20 cash (no idea about the catalog number, not on Numista)
Third row, middle:
Y# 37, most probably this one (without image):
https://en.numista.com/catalogue/pieces34856.html
Numista lists a replica token for it:
https://en.numista.com/catalogue/pieces41312.html
(I guess mine can be a replica too...)
Could anyone please correct / extend the information above?

i think mostly got them on the money with ID. Probably all real but as with most chinese coins counterfeits are possible, however just from picture i think they are okay even tho some of them are quite rare.