4 Maravedis 1617 coin i am not sure if this is the actual discription km#3 [Risolto]

Found this coin in a safe my mother owned and just want to know if anyone knows anything about it, I am having trouble finding a picture that is exactly like this coin. I am also curious if anyone would know a value for this coin as well, I look forward to any thought's on the coin. dmeza01

What is the diameter?
On the second image that is not IIII letters for 4 it is an aqueduct mintmark.
The denomination has been obliterated by the XII for 12 overstamp.

Maybe before the XII stamp it was VIII for 8 Maravedis.
This below (Segovia) has the 1617 date on the right of the lion like yours ...
https://www.ma-shops.com/cdma/item.php?id=512096
and is KM#16 reference.

This is 25.5mm
https://en.numista.com/catalogue/pieces67810.html

so what do you think the XII on the coin is you do not believe it was originally part of the coin that it was struck on it later. I am asking because i am very new to this i have many old coins not as old as this one but have no idea what they are worth or if it is a good coin to keep.

In times of inflation some coins, in various countries, were over-stamped with a different
denomination - such as maybe an 8 Maravedis was revalued to 12 Maravedis. So if prices
have risen that what used to cost 8 Maravedis was now 12 then the government recalled
all 8 Maravedis coins and over-stamped them with the new value; so the same coin could
buy the same items. And to show it was an official overstamp they sometimes put
another stamp on there - like on the other side of your coin, with that 64I which could
mean it was revalued, 24 years later - after Philip III, in 1641.
Something like that.
Examples on the first page here - there are a lot of countermarked coins, for same reasons ...
https://en.numista.com/catalogue/bresil-1.html

EDIT: Here is a page that at the top has information ...
http://forum.treasureclassifieds.com/Thread-1500-s-spanish-viii-maravedis-counter-stamped-xii-maravedis-1600-s#sthash.kHGRwF0U.dpbs

https://en.wikipedia.org/wiki/Countermark
Also, with a different coin though, this has information ...
https://finds.org.uk/database/artefacts/record/id/474629

This (1625) has the stamps (XII and 1641) both sides like yours, and it
has the XII at an angle, so that the VIII underneath can be seen a little ...
https://www.ma-shops.co.uk/an/item.php?id=430

Your coin is in Numista
https://en.numista.com/catalogue/pieces137749.html