Italy / Two Sicilies / Neapolitan Province Identification

I have in my collection what appears to be a Neapolitan Province #20. I know this forum has some experts in this area and I would like to hear some of your expertise regarding this issue. I ASSUME these issues, like many other classical issues, come with their fair share of forgeries. With me not having access to the information to make an informed decision as to this being a legitimate stamp vs a forgery, I would appreciate our SCF members' opinions.

Hi: In my opinion this stamp is authentic.Following tests passed..
1)Small line in upper frame between P & O
2)The P in Post ;in the P; thin line
3)Small vertical line below Bollo.
4)Small dot in lower left frame above cross
5)Upper part of R in Franco a bit narrow.
6)E in Post,Lower serif a bit heavy & long
A similar stamp below,better pic..


Well centered head:


Your stamp looks like Sassone No.18a grey-brown.7 colors types:
18 bistre brown
18a grey brown
18b dark grey brown
18bc black brown
18c brown greyish
18d brown
18e bistre brown on thick paper
Your stamp If mint ,it's expensive...

Good Afternoon Perf12. I thank you for your information. I have read many of your posts before concerning Italian/Italian States stamps and I thank you for your response. I do not have access to the Sassone Catalog that you referenced. Does it list the number of stamps printed for this one? While I researching it online I read the run was 20,100. My 2017 Scott Catalog lists this one as #20b (gray brown) with an unused value of $255. Does all of that sound about right?

I think that's about right but the price can vary depending on the
condition & centering & margins.